Podcast
Questions and Answers
Where does the signal of the corticospinal tract (CST) originate?
Where does the signal of the corticospinal tract (CST) originate?
Which part of the corticospinal tract is primarily responsible for fine, precise distal limb movements?
Which part of the corticospinal tract is primarily responsible for fine, precise distal limb movements?
What characterizes the initial symptoms of an upper motor neuron lesion?
What characterizes the initial symptoms of an upper motor neuron lesion?
Where is the anterior (ventral) corticospinal tract located?
Where is the anterior (ventral) corticospinal tract located?
Signup and view all the answers
A patient presents with contralateral paralysis and ipsilateral cranial nerve deficits. Which area of the central nervous system is most likely affected?
A patient presents with contralateral paralysis and ipsilateral cranial nerve deficits. Which area of the central nervous system is most likely affected?
Signup and view all the answers
Which descending tract primarily facilitates the activation of flexor muscle groups in the upper limbs?
Which descending tract primarily facilitates the activation of flexor muscle groups in the upper limbs?
Signup and view all the answers
A patient exhibits difficulty controlling neck and arm extensors. Which descending tract is MOST likely affected?
A patient exhibits difficulty controlling neck and arm extensors. Which descending tract is MOST likely affected?
Signup and view all the answers
The pontine reticulospinal tract primarily facilitates which type of movement?
The pontine reticulospinal tract primarily facilitates which type of movement?
Signup and view all the answers
Which tract originates in the red nucleus of the midbrain and supports upper limb flexion?
Which tract originates in the red nucleus of the midbrain and supports upper limb flexion?
Signup and view all the answers
Which of the following describes the primary function of the lateral corticospinal tract?
Which of the following describes the primary function of the lateral corticospinal tract?
Signup and view all the answers
The medullary reticulospinal tract plays a role in what specific function?
The medullary reticulospinal tract plays a role in what specific function?
Signup and view all the answers
A lesion to the lateral white matter of the spinal cord would most likely disrupt which tract?
A lesion to the lateral white matter of the spinal cord would most likely disrupt which tract?
Signup and view all the answers
Which of the following is most likely to be observed after a stroke of the motor cortex?
Which of the following is most likely to be observed after a stroke of the motor cortex?
Signup and view all the answers
A patient presents with a right homonymous hemianopsia. Which of the following locations is the most likely site of a lesion?
A patient presents with a right homonymous hemianopsia. Which of the following locations is the most likely site of a lesion?
Signup and view all the answers
Which of these does NOT describe the function of the middle ear?
Which of these does NOT describe the function of the middle ear?
Signup and view all the answers
What is the immediate effect of sound vibrations on the hair cells of the cochlea?
What is the immediate effect of sound vibrations on the hair cells of the cochlea?
Signup and view all the answers
Which of the following best describes a lower motor neuron lesion?
Which of the following best describes a lower motor neuron lesion?
Signup and view all the answers
Where are the cell bodies of the lower motor neurons located?
Where are the cell bodies of the lower motor neurons located?
Signup and view all the answers
In the muscle stretch reflex, which type of neuron directly innervates the muscle?
In the muscle stretch reflex, which type of neuron directly innervates the muscle?
Signup and view all the answers
What is a key function of the corticospinal tract (CST)?
What is a key function of the corticospinal tract (CST)?
Signup and view all the answers
Where do the medial brainstem pathways predominantly terminate?
Where do the medial brainstem pathways predominantly terminate?
Signup and view all the answers
What is a characteristic of the hypothalamic-pituitary-adrenal (HPA) axis in individuals with Major Depressive Disorder (MDD)?
What is a characteristic of the hypothalamic-pituitary-adrenal (HPA) axis in individuals with Major Depressive Disorder (MDD)?
Signup and view all the answers
Which area of the brain shows increased blood flow in individuals with Major Depressive Disorder (MDD)?
Which area of the brain shows increased blood flow in individuals with Major Depressive Disorder (MDD)?
Signup and view all the answers
What is the typical timing of symptom onset for Postpartum Depression?
What is the typical timing of symptom onset for Postpartum Depression?
Signup and view all the answers
In the neurobiology of anxiety disorders, where is activity typically reduced?
In the neurobiology of anxiety disorders, where is activity typically reduced?
Signup and view all the answers
What is the primary neurotransmitter associated with the reward pathway in substance use disorders?
What is the primary neurotransmitter associated with the reward pathway in substance use disorders?
Signup and view all the answers
An individual with a substance use disorder experiences tolerance. What does this mean?
An individual with a substance use disorder experiences tolerance. What does this mean?
Signup and view all the answers
Which of these is NOT a common characteristic of substance use disorders?
Which of these is NOT a common characteristic of substance use disorders?
Signup and view all the answers
Which area of the brain is considered the 'pleasure and reward center' that is affected by substance use?
Which area of the brain is considered the 'pleasure and reward center' that is affected by substance use?
Signup and view all the answers
What is the minimum number of attacks required for a diagnosis of migraine with aura?
What is the minimum number of attacks required for a diagnosis of migraine with aura?
Signup and view all the answers
Which of the following is NOT a characteristic of aura symptoms in migraine with aura, according to diagnostic criteria?
Which of the following is NOT a characteristic of aura symptoms in migraine with aura, according to diagnostic criteria?
Signup and view all the answers
Which of the following is characteristic of migraine with brainstem aura?
Which of the following is characteristic of migraine with brainstem aura?
Signup and view all the answers
A patient presents with a headache and aura symptoms, including temporary motor weakness. According to the provided information, what type of migraine is most likely?
A patient presents with a headache and aura symptoms, including temporary motor weakness. According to the provided information, what type of migraine is most likely?
Signup and view all the answers
According to the provided information, which of the following is considered the most prominent ‘red flag’ concerning patterns in a headache?
According to the provided information, which of the following is considered the most prominent ‘red flag’ concerning patterns in a headache?
Signup and view all the answers
Which of the following is NOT a typical episodic syndrome associated with migraine?
Which of the following is NOT a typical episodic syndrome associated with migraine?
Signup and view all the answers
Which of the following is considered a 'red flag' for headaches in the context of pregnancy or puerperium?
Which of the following is considered a 'red flag' for headaches in the context of pregnancy or puerperium?
Signup and view all the answers
What is the minimum duration for an individual aura symptom in a migraine with aura?
What is the minimum duration for an individual aura symptom in a migraine with aura?
Signup and view all the answers
A patient presents with contralateral paralysis of the face and arm, and sensory deficits in the same regions. Which artery is most likely involved?
A patient presents with contralateral paralysis of the face and arm, and sensory deficits in the same regions. Which artery is most likely involved?
Signup and view all the answers
Which clinical sign is most indicative of anterior cerebral artery (ACA) involvement?
Which clinical sign is most indicative of anterior cerebral artery (ACA) involvement?
Signup and view all the answers
If a patient experiences cortical blindness and homonymous hemianopia after a stroke, what cerebral artery is most likely affected?
If a patient experiences cortical blindness and homonymous hemianopia after a stroke, what cerebral artery is most likely affected?
Signup and view all the answers
A patient presents with a severe locked-in state post-stroke. Which artery is most likely affected, given this devastating symptom?
A patient presents with a severe locked-in state post-stroke. Which artery is most likely affected, given this devastating symptom?
Signup and view all the answers
A patient is diagnosed with aphasia following a stroke. This indicates a likely involvement of which region of the brain?
A patient is diagnosed with aphasia following a stroke. This indicates a likely involvement of which region of the brain?
Signup and view all the answers
Which set of symptoms is most indicative of vertebral artery (VA) involvement?
Which set of symptoms is most indicative of vertebral artery (VA) involvement?
Signup and view all the answers
A patient presents with contralateral leg and foot paralysis, which arterial supply is most likely affected?
A patient presents with contralateral leg and foot paralysis, which arterial supply is most likely affected?
Signup and view all the answers
If a patient has a stroke affecting the nondominant hemisphere resulting in unilateral neglect, which artery is most likely primarily involved?
If a patient has a stroke affecting the nondominant hemisphere resulting in unilateral neglect, which artery is most likely primarily involved?
Signup and view all the answers
Which symptom is not typically associated with a posterior cerebral artery (PCA) stroke?
Which symptom is not typically associated with a posterior cerebral artery (PCA) stroke?
Signup and view all the answers
A patient experiences new memory recall and retention problems after a stroke. Which artery is most likely involved, particularly affecting the deep cortical branches?
A patient experiences new memory recall and retention problems after a stroke. Which artery is most likely involved, particularly affecting the deep cortical branches?
Signup and view all the answers
Study Notes
Neurology: Part 2
- George Washington Carver quote about being tender with the young, compassionate with the aged, sympathetic with the striving, and tolerant of the weak and the wrong.
Nomenclature
- Anterior = Ventral
- Posterior = Dorsal
- Afferent = going to the brain (sensory neurons)
- Efferent = coming from the brain (motor neurons)
- Ganglion = group of cell bodies
- AP = action potential
- Transduction: conversion of stimulus to electrical impulse
- Transmission: propagation from the periphery to the CNS
- Perception: interpretation of impulse
Neurological Lesion Localization
- A condition of the brain is referred to as myelopathy.
- A condition of the brainstem is referred to as myelopathy.
- A condition of the cerebellum is referred to as myelopathy.
- A condition of the spinal cord is referred to as myelopathy.
- A condition of the nerve root is referred to as radiculopathy.
- A condition of the nerve is referred to as neuropathy.
- A condition of the neuromuscular junction is referred to as neuropathy.
- A condition of the muscle is referred to as myopathy.
Structure of the Spine
- The spinal nerves are regionally arranged as follows:
- 8 cervical pairs
- 12 thoracic pairs
- 5 lumbar pairs
- 5 sacral pairs
- 1 coccygeal pair
- Key nerve plexuses:
- Cervical: C1-C4
- Brachial: C5-T1
- Lumbar: L1-L4
- Sacral: L4-S4
Structure of the Spinal Cord
- Detailed diagram of spinal cord including anatomical labels.
Structure of Spinal Cord
- Detailed diagram of spinal nerve structure with labels.
Somatic Sensory Function
- Afferent neurons bring sensory information to the CNS.
- Afferent neurons respond to stimuli like touch, vibration, temperature, and pain.
- Action potentials (APs) are generated in response to stimuli and relayed to the CNS.
- Sensory relay occurs in the dorsal horn of the spinal cord.
Ascending Tracks
-
Detailed diagram of the Dorsal Column and Spinothalamic Tract pathways
-
Dorsal column: heavily myelinated, responsible for light touch, vibration, and proprioception.
-
Spinothalamic tract: small fibers, responsible for pain and temperature.
Sensory Pathway
-
Detailed diagram illustrating the sensory pathway components
-
Dorsal columns: responsible for light touch, vibration, and position sense.
-
Dorsal root ganglion: first-order neurons enter these columns
-
Move up brain stem to sensory nuclei (second-order neurons)
-
Move up to the thalamus (third-order neurons)
-
Sensory exam: decreased light touch, vibration, and changes in position sense.
Sensory Pathway - Spinothalamic Tract
- Spinothalamic tract: fibers with length-dependent involvement, responsible for pain sensation.
- Enter lateral dorsal root and synapse in dorsal horn.
- Sensory exam: decreased pin prick and temperature.
- Thalamic neurons receive input, project to somatosensory cortex.
Question 1
- The correct answer is (a) Ability to correctly discriminate location of sensory stimulus by the dorsal column/medial lemniscus system.
Sensory Pathophysiology
- Neuropathy is a result of damage to peripheral nerves.
- Small fiber dependent on involvement of the spinothalamic tract
- Proximal involvement of dorsal column
- Mixed: pansensory
### Clinical Vignette 1
- A 72-year-old female with a history of T2DM and Hemoglobin A1C of 8, presenting with increasing falls.
- Exam findings: ankle jerk absent bilaterally, decreased vibration and pinprick bilaterally (D>P). Romberg positive.
Diabetic Neuropathy
- Overview of diabetic neuropathy and common symptoms.
- Various parts of the body and mechanisms that can be affected.
Pain
- Overview of nociceptors.
Nociceptors (Peripheral)
-
Two categories of fibers:
- Aδ: myelinated axons; conduct at 5-30 m/sec; mechanosensitive and mechanothermal.
- C: unmyelinated axons; conduct at 2 m/sec; polymodal.
-
Types of nociceptors
-
Nociceptors respond to intense mechanical and thermal stimuli
-
Release glutamate at their synaptic targets
-
May release substance P, which produces slower and longer-lasting excitation
Ascending Pain Pathway: Pain Modulation
- Primary activation: direct activity of inflammatory mediators on nociceptors
- Secondary activation: release of substance P and recruitment of immune response.
- Inflammatory mediators involved: bradykinin, histamine, serotonin, arachidonic acid, nerve growth factor.
Neurophysiology of Pain: Nociception
- Nociceptors: peripheral sensory neurons activated by tissue-damaging stimuli. They release glutamate in synapses with spinothalamic tract neurons.
- Spinothalamic tract neurons: located in the dorsal horn of the spinal cord. Their axons project to the thalamus and brainstem reticular formation
- Thalamocortical relay neurons project to the somatosensory cortex for recognition and localization of pain.
- Parallel pathways exist for emotional and physical response to pain.
Spinothalamic Tract Neurons: Recap
- Ascend to brainstem and thalamus.
- Transmit pain signals to midbrain, pons, and medulla.
- Activate limbic areas, insular cortex, and anterior cingulate cortex
- Provide cognitive-evaluative processing
- Third-order neurons project to somatosensory cortex for recognition and localization.
Question 2
- The correct answer is a (Acetylcholine).
Pain Pathway: Pain Modulation
- Periaqueductal gray (PAG) produces analgesia; it contains endogenous opioids (enkephalins, endorphins, and dynorphins).
- Release of substance P and glutamate is reduced.
- Neurons project to medulla; norepinephrine and serotonin are released at synapses in the dorsal horn, further inhibiting action potentials (APs).
Gate Theory of Pain
- Activation of low-threshold touch or mechanoreceptors associated with Aβ axons.
- Nociceptive information through spinal cord is moderated by simultaneous activation of low-threshold touch receptors.
- Example: rubbing a stubbed toe enhances the pain relief.
Placebo Effect
- Physiological response to pharmacologically inert therapy.
- Brain regions related to opioid transmission are activated by the placebo.
- Dorsolateral prefrontal cortex, rostral cingulate cortex, hypothalamus, and periaqueductal gray (PAG) become involved.
- Endogenous opioids are responsible for this pain modulation.
Sensitization
- Peripheral: local inflammatory mediators increasing APs.
- Hyperalgesia: severe pain from slightly painful stimuli.
- Central: excitability of neurons in the dorsal horn following high activity levels.
- Allodynia: pain from non-painful stimuli due to overexcitability.
Referred Pain
- Visceral pain signals reach the spinal cord at the level associated with organ innervation.
- Pain is reflected as somatic pain.
Question 3
- The correct answer is (d) Gate theory of pain.
Pharmacological Modulation of Pain
- NSAIDs inhibit cyclooxygenase (COX) enzyme, impairing arachidonic acid transformation into prostaglandins.
- Opioids modulate pain when bound to receptors, reducing substance P and nociceptive transmission in the anterior horn.
- PAG-descending modulatory inputs
- Nucleus accumbens—reward center.
- Nonpharmacological approaches include exercise, psychological therapies, mindfulness, and multidisciplinary rehabilitation.
Ascending Tracts
- Dorsal Column: Origin - Sensory receptors; Fiber Size - Large; Function - Light touch, proprioception, vibration, two-point discrimination; Crossing - Ipsilateral; Termination - Somatosensory cortex.
- Spinothalamic: Origin - Sensory receptors; Fiber Size - Small; Function - Pain and temperature sensing; Crossing - Contralateral; Termination - Somatosensory cortex, parallel pathways in the limbic system.,
Clinical Vignette 2
- A 44-year-old female with multiple sclerosis, experiencing severe, intermittent left-sided pain, and a rash consistent with shingles.
Clinical Vignette 2: Primary infection, latent infection, immune response, and herpes zoster.
- The details of a primary varicella-zoster virus (VZV) infection, its latent period in sensory ganglia, and the immune response that controls VZV infections.
Special Senses
- Overview of the special senses.
Visual System
- Cranial nerve II (optic nerve)
- Visual acuity
- Intracranial pressure via direct inspection of optic nerve
- Cranial nerves III, IV, and VI
- Responsible for extraocular movements
- Evaluate for diplopia, nystagmus, and ptosis
Visual Pathway
- Each retina is divided into nasal and temporal retinas.
- Left visual field projects to nasal retina of left eye and temporal retina of right eye.
- Right visual field projects to the temporal retina of the left eye and the nasal retina of the right eye.
- Refraction of light through the biconvex lens.
- Optic nerves cross at the optic chiasm.
- Signals are transmitted on optic tracts to the lateral geniculate bodies.
- Project to the visual cortex in the occipital lobe, enabling visual processing.
Visual Pathway
- Optic nerves transmit signals posteriorly and cross at the optic chiasm.
- Tracts transmit signals to lateral geniculate bodies.
- Optic radiations project to visual cortex in occipital lobe.
Visual Field Deficits
- Overview of visual field deficits and their locations.
- Types of visual field defects from different lesions.
- Different patterns of visual field defects from specific lesions, including complete blindness in the right eye due to a lesion on the optic nerve, to bipolar hemianopsia due to a midline lesion on the optic chiasm, a right nasal hemianopsia due to a lesion on the right perichiasmal area, to homonymous hemianopsia on the left due to a lesion on the right occipital lobe.
Clinical Vignette 3
- An 80-year-old male with a history of hypertension, experiencing vision loss and left-sided numbness.
- Examination reveals left homonymous hemianopsia.
Clinical Vignette 3: Understanding lesion location based on visual field deficits.
- Determining the probable location of a lesion in the brain that led to the patient's left homonymous hemianopsia
The Two Pairs of Arterial Supply
- Anterior cerebral artery (ACA)
- Middle cerebral artery (MCA)
- Posterior cerebral artery (PCA)
- Basilar artery
- Vertebral artery
Cerebral Blood Circulation
- Diagram illustrating the anterior cerebral artery (ACA).
- Diagram illustrating the middle cerebral artery (MCA).
- Diagram illustrating the posterior cerebral artery (PCA)
Meet HAL
- Diagram depicting the motor and sensory cortices in the brain.
- Illustrates the topographic organization
- Relationship between the different arteries and their supply areas in the cerebral cortex.
Intracranial Circulation
- Overview of the intracranial circle of Willis.
Question 10
- The anterior cerebral artery supplies the medial frontal cortex.
- A stroke affecting this artery results in weakness of the foot and leg
Artery, Cerebral Cortex, and Signs & Symptoms - Anterior Circulation
- ICA supplies the frontal lobe (including the motor and sensory cortices)
- ACA: Contralateral paralysis of the face, arm, leg. Sensory deficits in the face, arm, and leg.
- MCA: Contralateral paralysis of the face and arm Sensory issues in the face and arm, Aphasia when the dominant hemisphere is affected.
Artery, Cerebral Cortex, and Signs & Symptoms - Anterior Circulation
- Includes the MCA branches; the M1 branch supplying the lateral frontal cortex; stroke leads to contralateral paralysis of the face and arm
- Sensory deficits in the face and arm; aphasia (global aphasia with dominant hemisphere)
- Aphasia if the dominant hemisphere is affected
- Apraxia, agnosia, and contralateral neglect (of the non-dominant hemisphere)
- Homonymous hemianopsia
Artery, Cerebral Cortex, and Signs & Symptoms - Posterior Circulation
- VA and BA: dizziness, nystagmus, dysarthria, dysphagia; Ipsilateral face (and sometimes nasal area) weakness and numbness
- Paralysis of all four extremities
- Patient is typically in a pseudocoma or locked-in scenario.
- Paresis of facial, tongue and swallowing muscles
Artery, Cerebral Cortex, and Signs & Symptoms - Posterior Circulation
- PCA: homonymous hemianopsia or cortical blindness; cognitive deficits involving memory recall and retention.
Posterior Circulation
- Visual disturbances, cortical blindness, memory issues, and difficulty with retaining new and recent memories.
Clinical Vignette
- 56-year-old female presenting with dizziness, gait disturbance, and near syncope.
- No recent trauma or aura.
- Medical history of episodic migraine and hypertension
Clinical Vignette
- A patient presented with acute-onset, continuous dizziness and gait disturbance.
- Previous history of episodic migraine and hypertension.
- Negative findings of nystagmus and the HINTS test suggest no brainstem or cerebellar involvement.
Motor Activity
- Spinal motor neurons are responsive to feedback from muscles, tendons, and pain sensors.
- Motor cortex controls voluntary movement; brainstem pathways regulate muscle tone and unconscious adjustments.
Lower Motor Neurons
- Cell bodies of lower motor neurons are located in the ventral horn of the spinal cord gray matter.
- Descending motor pathways are found in the white matter.
- Motor neurons are efferent and bring information from the CNS to the periphery
Lower Motor Neurons
- Cervical and lumbar enlargements cluster target muscle groups together.
- Most medial neurons control axial muscles.
- Girdle muscles are controlled by neurons lateral to the axial group.
- Limb muscles are controlled by neurons lateral to the girdle muscles.
- Flexors (lateral), and extensors (medial) in terms of location.
Neuromuscular Junction (NMJ)
- Synapse between the motor neuron and target muscles.
- Postsynaptic membrane with nicotinic acetylcholine receptors.
- Acetylcholine binding at receptors causes Na+ influx into the muscle, depolarizing the membrane.
- Voltage-gated Ca++ channels open facilitating crossbridge formation
- Myasthenia gravis is an autoimmune reaction to these receptors.
Lower Motor Neuron Lesions
- Motor neurons in the brainstem and spinal cord
- Upper motor neurons are in the motor cortex
- Pathology in skeletal muscle contraction
- EMG reveals disorganized low-level electrical activity (fibrillation).
Motor Neuron Disease: Signs and Symptoms
- Table showing the differences between upper and lower motor neuron disease in relation to weakness, atrophy, fasciculations, reflexes, and tone.
Muscle Reflex Circuit
- Muscle spindle sensory fiber (Ia fiber): proprioceptor, AP proportional to length and velocity of stretch, heavily myelinated.
- GTO (Ib fiber): releases GABA on motor neuron, helps tune movement..
- Motor neuron releases acetylcholine at the NMJ, thereby creating the stretch reflex.
Clinical Vignette 4
- 32-year-old female with increasingly clumsy hands with gait issues.
- Hyper-reflexia throughout, sensation is intact.
- Strength is 4/5, Spastic gait.
Clinical Vignette
- Upper motor neuron lesion due to cervical myelopathy at C6-7.
Descending Tracts: Overview
- Descending motor tracts originating in the pons and medulla.
Descending Tracts: Pons and Medulla
- Vestibulospinal Tract: Origin - Vestibular nuclei; Function - Controls neck and arm extensors, antigravity; Crossing - Ipsilateral limbs, and bilateral neck; Termination - Lower motor neuron.
- Reticulospinal Tract: Origin - Pontine reticular formation and Medullary reticular formation; Function - Activates limb extension; inhibits limb extension; Crossing - Ipsilateral; Termination- Lower motor neuron.
Descending Tracts: Cortex
- Corticospinal Tract (Lateral): Origin - Motor cortex; Function - Distal muscle activation; Crossing - Contralateral; Termination - Lower motor neuron.
- Rubrospinal Tract: Origin - Red nucleus; Function - Proximal and axial muscle activation, upper limb flexion; Crossing - Contralateral; Termination- Lower motor neuron.
Question 5
- The correct answer is (b), impaired rapidly alternating movements
Basal Ganglia
- Initiates and refines movement
- Multi-step process that begins in the premotor cortex
- Glutamate neurons in the motor cortex project to striatal acetylcholine interneurons
- Striatal interneurons excite GABA neurons projecting from the striatum to the globus pallidus.
- Dopamine neurons oppose the excitatory effects, inhibiting GABA output from the striatum.
- Two pathways exist: direct and indirect pathways.
Parkinson's Disease
- Neurodegenerative disorder resulting from dopamine-producing neuron loss in the substantia nigra.
- Causes overactivity of excitatory acetylcholine transmission in the striatum
- Associated with akinesia, bradykinesia, and increased muscle tone (rigidity).
- Cause is often unknown, but some cases are linked to specific gene mutations.
- Treatment focuses on restoring dopamine, blocking acetylcholine receptors, or stimulating dopamine receptors.
Clinical Manifestions of PD
- Motor symptoms: tremor, rigidity, akinesia/bradykinesia, postural instability.
- Nonmotor symptoms: depression/apathy, anxiety, constipation, urinary dysfunction, insomnia, orthostatic hypotension, and cognitive decline.
Parkinsonism
- Classification of subtypes of Parkinson's disease.
- Idiopathic Parkinson's Disease
- Atypical parkinsonism
- Drug-induced Parkinsonism
- Structural causes of parkinsonism.
Clinical Vignette 5
- An 80-year-old male with Parkinson's disease, presenting with increasing falls and "off" periods are more frequent than "on" periods.
Cerebellum
- The cerebellum is involved in quality control of movement.
- It assists in creating movement plans by receiving input from proprioceptors and providing this input to the motor cortex
- Cerebellar pathologies can result from vascular trauma, masses, or congenital causes.
Cerebellar Pathology
- Clinical manifestations:
- Ataxia (uncoordinated movement)
- Dysmetria (fluctuation between over and undershooting a target)
- Dysdiadochokinesia (inability to conduct rapid alternating movement)
- Intention tremor (worsening near the target)
Summary of Motor Disorders
- Summarizes different motor disorders across various parameters such as muscle strength, tone, atrophy, reflexes, gait, and posture/balance.
- Includes specific examples like upper and lower motor neuron lesions, parkinson's Disease, and cerebellar disease.
Question 6
- Acetylcholine
Higher Functions of the Nervous System
- Overview of higher executive functions.
- Neuroanatomy of higher executive functions, including the prefrontal cortex (PFC).
- Brain pathways, neurotransmitters and output systems.
- Altered brain characteristics in depression, including cortisol levels, and biological actions of antidepressants.
- Focus on dopamine and its input to the nucleus accumbens, including its role in substance use disorders.
- Evidence for endogenous opioid and cannabinoid-like substances in brain function
Anatomy of Cognition and Behavior
- PFC:
- Dorsomedial PFC: Reality testing, error monitoring.
- Dorsolateral PFC: Top-down guidance of attention.
- Rostrolateral PFC: Inhibition of inappropriate actions.
- Ventromedial PFC: Regulating emotion.
- OFC: Holistic sense of the environment, closely linked to limbic system.
Brain Mechanism of Stress
- Brainstem structures activate stress effector systems (e.g., sympathetic nervous system, hypothalamic-pituitary-adrenal (HPA) axis).
- Central neurotransmitters (e.g., norepinephrine, corticotropin-releasing hormone) from the locus ceruleus and paraventricular nucleus initiate the stress response.
- Activation increases physiological responses (sympathetic nervous system activity, blood pressure).
Brain Circuit Flip
- Diagrams illustrate how the brain reconfigures pathways during stress.
- Shift from normal prefrontal regulation pathways to emotional pathways involving the amygdala.
Question 7
- The correct answer is (a), activation of norepinephrine neurons in the locus ceruleus.
Neurobiology of Depression
- Major depressive disorder is the most common mental health disorder, characterized by HPA axis abnormalities, daily cortisol level elevation, decreased PFC blood flow and increased Amygdala blood flow.
Postpartum Depression
- 85-90% of females affected; 10-15% severe.
- Symptoms within 4 weeks of delivery.
- Risk for affective illness elevated up to 1 year post-delivery.
Neurobiology of Anxiety
- Common mental disorder with high prevalence.
- Neurobiological studies implicate the amygdala, hippocampus, insula, anterior cingulate, and ventromedial PFC.
- Activity is reduced in the dorsolateral PFC.
Substance Use Disorders
- Increased dopamine release from VTA neurons to the nucleus accumbens.
- Individuals with substance use disorders exhibit compulsive pattern: tolerance, cravings, withdrawal..
Question 8
- The correct answer is (a), The release of dopamine in the nucleus accumbens is reinforcing.
Pediatric Considerations
- Overview of pediatric considerations in a neurological context, highlighting brain development, seizures, and neurological disorders prevalent in the pediatric age group
Objectives: Part 4
- Brief description of brain development; definition of seizures and epilepsy; examples of types of seizures and epilepsy; comparison of major headache types and hypotheses of these; optimal care for concussion.
Brain Development
- Beginning in the third week of gestation, neurons rapidly multiply up to 4-12 weeks.
- Neuronal numbers total about twice adult levels during that period.
- Apoptosis begins at about week 16
- Myelination begins before birth and peaks years after.
- Development of critical sensory and motor milestones
- Crucial for neurodevelopmental milestones.
Brain Development
- Chronological stages of brain development.
Spinal Muscular Atrophy
- Second most frequent genetic disorder in childhood; mutation of SMN1 gene;
- Most common type is SMA 1 (autosomal recessive); survival around 2 years;
- Symptoms: muscle weakness, especially affecting the diaphragm and muscles of the limbs.
Spinal Muscular Atrophy
- The details of SMA, its genetic etiology, and pathophysiological mechanisms affecting spinal motor neurons.
Neonatal Seizures
- Causes: hypoxic-ischemic encephalopathy, strokes, intracranial hemorrhage, inborn metabolic errors, genetic disorders, intracranial infection, and malformation syndromes.
- Development of immature neurotransmitter systems.
- Differential diagnosis between neonatal and adult seizures.
Pediatric Febrile Seizures
- Associated with fever and an infection; No evidence of intracranial infection;
- Usual onset ages 6 months-6 years old; Seizure duration—simple (< 15 minutes) and complex (< 15 minutes);
- No postictal neurological defects; Causes high parental anxiety.
Development and Intellectual Disability
- Disorders associated with developmental and intellectual disability like autism spectrum disorder; Down syndrome, and fragile X syndrome.
Dx Criteria for Migraines
- Two criteria must be met for migraine diagnosis: 4-72 hour headache, unilateral location, pulsating quality, moderate to severe pain, and/or worsened by routine activities.
- Nausea or/and vomiting are present.
- Photophobia and/or phonophobia (sensitivity to light or sound).
- The patient must have 5 or more attacks for a diagnosis.
Dx Criteria for Migraine w/ Aura
- Two attacks with aura; at least three characteristics
- At least one aura symptom should spread for 5 minutes or more.
- Two or more aura symptoms in sequence.
- Each symptom lasting 5-60 minutes.
- At least one aura symptom can be unilateral
- Aura symptom is positive
- Aura is followed or accompanied by headache
Migraine with Aura: Subtypes
- Migraine with brainstem aura (formerly basilar migraine) presenting with symptoms from brainstem involvement.
- Hemiplegic migraine, with motor weakness/ neurological manifestations.
- Retinal migraine (formerly ocular migraine), with primary visual disturbances such as monocular visual disturbance, scintillations, scotomata or blindness.
PIN the Diagnosis: ID Migraine™
- Photophobia: whether light bothers a person with a headache.
- Impairment (Disability): If a headache limits activities.
- Nausea: if nausea is experienced.
- 2 out of 3 symptoms: 93% Positive Predictive Value (PPV)
- 3 out of 3 symptoms: 98% PPV
Causes of Secondary Headache
- Etiologies (Neoplastic Infections vascular, Low-/High-pressure syndromes, drug-induced, and idiopathic)
- Examples in each category including primary vs. metastatic brain neoplasms, meningitis or other infections, subarachnoid hemorrhage, etc.
SNNOOP10: Red and Orange Flags in Headache
- systemic signs and symptoms
- Neoplasia in history
- Neurologic deficit
- Onset sudden
- Older age (>50)
- Pattern change
- Positional change
- Precipitated by specific events
- Papilledema
- Progressive headache
- Pregnancy, puerperium
- Autonomic features with painful eye
- Posttraumatic
- Immune system issues
- Painkiller overuse
Episodic Syndromes Associated With Migraine
- Recurrent GI disturbances; benign paroxysmal vertigo; benign paroxysmal torticollis.
Treatment Considerations: Migraine
- Lifestyle modifications (various methods).
- Acute migraine treatments (various pharmacologies).
- Preventative migraine treatments (various pharmacologies, medication use (contraceptives), antidepressants, triptans).
Sports Related Concussion
- Pathophysiological changes are induced by biomechanical forces such as potassium accumulation, depolarization, glutamate release, and excitotoxicity.
- Clinical manifestations: rapid onset of impaired neurological function.
- Treatment includes physical and cognitive rest with a gradual return to sports activities.
### Question 9
- The correct answer is (d), there is an increased incidence of headaches.
Gerontological Considerations
- Description of normal brain changes with aging and pathological aging due to various diseases.
- Cerebral circulation and its implications for strokes in the elderly.
- Effects of strokes on various brain regions in the elderly.
Neurodegenerative Disorders
- Neuronal networks are progressively impaired
- Pathologic changes in Alzheimer's Disease (AD).
- Beta-amyloid (Aβ) protein plaques between neurons.
- Presence of tau protein within axons, forming neurofibrillary tangles.
Acute Stroke Principles
- Achieves timely recanalization of the occluded artery and reperfusion of the ischemic tissue.
- Optimizes collateral flow.
- Avoids secondary brain injury.
Stroke Epidemiology
- Stroke has dropped to 5th leading cause of death in the US.
- Annual incidence of 795,000 strokes; 610,000 first/new strokes, 185,000 recurrent strokes.
- Leading cause of long-term disability.
NIH Stroke Scale (NIHSS)
- 15 exam components used to objectively evaluate the various deficits of patients with stroke to aid in communications with other providers.
Two Pairs of Arterial Supply
- Internal Carotid Arteries (ICA), Middle Cerebral Arteries (MCA), Posterior Cerebral Arteries (PCA), the Basilar Artery (BA) and the Vertebral Arteries (VA)
Cerebral Blood Circulation
- Overview of the cerebral blood circulation and its components including the anterior, middle, and posterior cerebral arteries.,
Meet HAL
- Overview of the motor and sensory cortices in the brain and their topographical organization in relation to different body parts.
- Diagram illustrating the cortical areas supplied by the different cerebral arteries.
Intracranial Circulation
- A detailed diagram of the intracranial vasculature.
- The interconnected arterial networks, providing redundant blood flow.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
This quiz focuses on the corticospinal tract (CST) and its roles in movement and motor control. It covers the origins, specific functions, and associated symptoms of upper motor neuron lesions related to the CST. Test your knowledge of neuroanatomy and the descending pathways involved in fine and precise movements.
