PT-PNS 301-Lecture 1 Applied Neuroanatomy and Neurophysiology PDF

PT-PNS 301-Lecture 1 Applied Neuroanatomy and Neurophysiology Dr. Sukumar Shanmugam Dr. Meruna Bose December 8, 2024 www.gmu.ac.ae COLLEGE OF ALLIED HEALT...

PT-PNS 301-Lecture 1 Applied Neuroanatomy and Neurophysiology Dr. Sukumar Shanmugam Dr. Meruna Bose December 8, 2024 www.gmu.ac.ae COLLEGE OF ALLIED HEALTH SEIENCES  OBJECTIVES At end of this lecture, the student can Describe the different parts of nervous system Differentiate LMN and UMN neurons Explain the functional areas of brain LOBES OF CEREBRUM The lobes of the cerebral hemispheres Planning, decision Sensory making speech Vision Auditory Motor/Sensory Cortex Sensory Areas – Sensory Homunculus TRACTS  NEUROPHYSIOLOGY OF MOVEMENTS Lower reflex arc works for basic movement Higher centers works for voluntary movements Feedback mechanisms works for errorless movements  REFLEX Efferent Response to an Afferent Stimulus COMPONENTS OF REFLEX MS spindles Fast-conducting Aα (Ia) and Aβ (II)nerve fibers Alpha motor neurons in AHCs. Axons of alpha motor neurons. Extrafusal ms fibers MS contraction. GTO, higher centers Alpha and Gamma neurons (Reflex physiology)  REGULATION OF MUSCLE TONE Pyramidal system Facilitation of AHC of spinal cord and motor nucleus of the brainstem Extrapyramidal system Regulation of muscle tone Symptoms of LMNL vs. UMNL  LMN vs. UMN Upper Motor Neurons (UMN) All the neurons contributing to the pyramidal and extrapyramidal systems Lower Motor Neurons (LMN) The anterior horn cells and the related neurons in the motor nuclei of some cranial nerves Axons of these cells give rise to the peripheral motor nerves.  SIGNS OF UPPER MOTOR NEURON LESIONS (UMNL) Paralysis or weakness of movements of the affected side but gross movements may be produced. No muscle atrophy is seen initially but later on some disuse atrophy may occur. Babinski sign is present: The great toe becomes dorsiflexed and the other toes fan outward in response to sensory stimulation along the lateral aspect of the sole of the foot. The normal response is plantar flexion of all the toes.  SIGNS OF UPPER MOTOR NEURON LESIONS (UMNL) Loss of performance of fine-skilled voluntary movements especially at the distal end of the limbs. Superficial abdominal reflexes and cremasteric reflex are absent. Spasticity or hypertonicity of the muscles. Clasp-knife reaction: initial higher resistance to movement is followed by a lesser resistance Exaggerated deep tendon reflexes and clonus may be present. SIGNS OF LOWER MOTOR NEURON LESIONS (LMNL) Flaccid paralysis of muscles supplied. Atrophy of muscles supplied. Loss of reflexes of muscles supplied. Muscles fasciculation (contraction of a group of fibers) due to irritation of the motor neurons – seen with naked eye. Muscle fibrillation (contraction of individual fibers) – detected only by EMG SIGNS OF LOWER MOTOR NEURON LESIONS (LMNL) Muscle contracture (shortening of paralyzed muscles) Presence of muscle wasting Reaction of degeneration: Muscle will no longer respond to interrupted electrical stimulation 7 days after nerve section, although it will still respond to direct current. After 10 days, response to direct current also ceases.  Clinical signs UMN lesion LMN lesion Muscles Affected In group Individual Reflexes- DTR Hyper reflexive Hypo reflexive Reflexes-superficial Hypo reflexive Hyper reflexive/normal Muscle Tone Spastic Flaccid Atrophy None Severe Nerve Conduction Normal Abnormal Studies Fasciculation None Present Pyramidal & Extra Pyramidal Symptoms Assessment Pyramidal Extra Pyramidal Muscle Tone Spastic Rigidity Distribution of Tone Upper Limb – Flx Generalised Lower Limb - Ext (predominated in Flx) Involuntary Movement Absent Present (Tremor, Chorea, Athetosis, Dystonia) Tendon Reflex Increased Normal / Slight Babinski Present Absent Paralysis of voluntary movement Present Absent / Bradykinesia COMMON SENSORY SYMPTOMS  SPECIAL SENSE Eye ◦ Anopia-defect in visual field ◦ Hemi Anopia- defect in vertical half of visualfield. Ear ◦ Auditory Agnosia – inability to interpret auditory sensation Nose ◦ Anosmia- inability to smell  ALERTNESS Coma: state of profound unconsciousness from which one cannot be roused; may be due to the action of an ingested toxic substance or of one formed in the body, to trauma, or to disease. Stupor: state of impaired consciousness in which the patient shows a marked diminution in reactivity to environmental stimuli and can be aroused only by continual stimulation. Lethargy: Relatively mild impairment of consciousness resulting in reduced alertness and awareness; this condition has many causes but is ultimately due to generalized brain dysfunction General Symptoms Epilepsy ◦ Chronic disorder characterized by paroxysmal brain dysfunction due to excessive neuronal discharge, and usually associated with some alteration of consciousness Romberg Sign ◦ When a patient, standing with feet approximated, becomes unsteady or much more unsteady with eyes closed. Open, it is a sign of proprioception loss Nystagmus ◦ Involuntary sideward movements of the eye Dysarthria Disarticulation in speech Dysphagia Difficulty in swallowing Cognitive & Perceptive Symptoms Apraxia: ◦ Impairment of the performance of known skilled or purposeful movements Agnosia: ◦ Prosapagnosia – Inability to identify familiar face ◦ Anagnosia – Inability to identify familiar objects ◦ Color Agnosia - Inability to identify familiar colous ◦ Finger Agnosia - Inability to identify own fingers ◦ Unilateral neglect – Reduced attention towards affected side ◦ Astereognosis – Lack of stereognosis Spatial and Temporal Issues  EXECUTIVE FUNCTIONS OF CORTEX Aphasia- difficulty in speech or language Amnesia / Fugue - loss of memory Behavioral Changes Dyslexia – Difficulty in learning Acalculia / Dyscalculia difficulty in calculation Psychosis / Neurosis- loss of thinking,emotions and reality Depression- Persistent feeling of sadness and loss of interest. Amnesia / Fugue ◦ A disturbance in the memory of stored information of very variable durations, minutes to months, in contrast to short-term memory, manifest by total or partial inability, to recall past experiences Dyslexia ◦ Impaired reading ability with a competence level below that expected on the basis of the person's level of intelligence, and in the presence of normal vision, letter recognition, and recognition of the meaning of pictures and objects Dyscalculia ◦ Difficulty in performing simple mathematical problems; commonly seen in parietal lobe lesions. COMMON ASSESSMENT TOOLS Muscle tone: Deep Tendon Reflexes Grading 0 = no response 1+ = present but depressed, low normal 2+ = Average, normal 3+ = Increased, brisker than average; possibly but not necessarily normal 4+ = very brisk, hyperactive with clonus; abnormal Ref: Table 8.3 page 237 O’Sullivan  MUSCLE POWER Manual Muscle Testing Grades (MRC) 0- absent 1- flicker of contraction 2- ROM in gravity eliminated 3- ROM in agility against 4- ROM against gravity with minimal resistance 5- ROM against gravity with maximal resistance Not applicable for CNS disorders Not appropriate for spasticity  VOLUNTAR CONTROL BRUNNSTROM’S 6 STAGES OF RECOVERY 1. Flaccidity, no voluntary movement 2. Synergies or minimal voluntary movement 3. Synergies performed voluntarily 4. Some deviation from synergy 5. Independent or isolated movement 6. Individual joint movement nearly normal with minimal spasticity  STATIC BALANCE GRADING Grade Description NORMAL Able to maintain balance against maximal resistance GOOD Able to maintain balance against moderate resistance G-/ F+ Accepts minimal resistance FAIR Able to sit unsupported without balance loss and without UE support POOR+ Able to maintain with minimal assistance from individual or chair POOR Unable to maintain balance – requires mod/max support from individual or chair  DYNAMIC BALANCE GRADING Grade Description NORMAL Able to sit unsupported & weight shift across midline maximally GOOD Able to sit unsupported & weight shift across midline moderately G-/ F+ Able to sit unsupported and weight shift across midline minimally FAIR Minimal weight shifting ipsilateral/front, difficulty crossing midline FAIR- Reach to ipsilateral side and unable to weight shift POOR+ Able to sit unsupported with min A and reach to ipsilateral side, unable to weight shift POOR Able to sit unsupported with Mod A and reach ipsilateral/front – can’t cross midline  MULTIMODAL SENSORY TESTING File:Somatosensation.jpg. (2019, October 31). Physiopedia, SENSORY GRADING  PROPRIOCEPTION TESTING Romberg’s test: Heel-shin Ataxia Finger—nose—finger test Distal proprioception test A contralateral joint matching task File:Somatosensation.jpg. (2019, October 31). Physiopedia, ORDER OF PROPRIOCEPTION TESTING  BASIC ADLs Walking (ambulating) ability to get around the home or outside. Feeding, ability to get food from a plate into one’s mouth. Dressing and grooming, ability to select clothes, putting them on, and adequately managing one’s personal appearance. Toileting, ability to get to and from the toilet, using it appropriately, and cleaning oneself. Bathing, ability to wash one’s face and body in the bath or shower. Transferring, ability to move from one body position to another. This includes being able to move from a bed to a chair, or into a wheelchair. This can also include the ability to stand up from a bed or chair in order to grasp a walker or other assistive device.  INSTRUMENTAL ADLs Require more complex thinking skills, including organisational skills. Managing finances, such as paying bills and managing financial assets. Managing transportation, either via driving or by organising other means of transport. Shopping and meal preparation. ie everything required to get a meal on the table. It also covers shopping for clothing and other items required for daily life. Housecleaning and home maintenance. Cleaning kitchens after eating, maintaining living areas reasonably clean and tidy, and keeping up with home maintenance.  FUNCTIONAL MEASURES Basic Activities of Daily Living (BADL) 1. Katz Index of ADLs 2. Barthel ADL Index Instrumental Functional independence measure 1. LLFDI - Late Life Function and Disability Instrument 2. SF-36 (proprietary; overview on website) 3. FSQ -- Functional Status Questionnaire 4. Lawton-Brody IADL Scale Functional Mobility instruments 1. Functional Independence Measure (FIM) FIM is proprietary. See O'Sullivan 6th ed. p.325 Terminology: definitions for Levels of Assistance O’Sullivan SB, Schmitz TJ, Fulk GD (Eds.). (20014). Physical rehabilitation. (6th ed.). Philadelphia: F. A. Davis Company 2. Physical Mobility Scale (see Appendix on p.98) Pike E, Landers MR. (2010). Responsiveness of the physical mobility scale in long-term care facility residents. J Geriatr Phys Ther. 2010 Apr-Jun;33(2):92-8. REFERENCES 2. Susan O’ Sullivan - Physical medicine and Rehabilitation 3. Rothstein – The rehab specialist’s Hand Book 4. John Pattern – Differential Diagnosis in Neurology 5. Davidson’s – Principles of Medicine Thank you