Medicine Marrow Pg No 577-586 (Neurology)

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Questions and Answers

Which of the following statements about the basal ganglia pathways is correct?

The indirect pathway is primarily activated through D1 receptors.

The subthalamus is an inhibitory nucleus in the basal ganglia.

The striatum receives excitatory input from the cortex. (correct)

All output from the cortex goes to GPi.

The nigrostriatal pathway activates the indirect pathway through D2 receptors.

False

What condition is characterized by degeneration of the nigrostriatal pathway?

Parkinson's disease

A common symptom of Parkinson's disease includes _____ of movement.

akinesia Signup and view all the answers

What is the most common type of Frontotemporal Dementia?

Behavioral variant Signup and view all the answers

Match the following terms to their respective features:

Hyperkinetic = Paucity of movement D1 Receptors = Activates direct pathway Subthalamus = Only excitatory nucleus Bradyphrenia = Slowness of thoughts Signup and view all the answers

Diffuse Lewy Body Dementia is the most common cause of dementia.

False Signup and view all the answers

What is the age of onset for Frontotemporal Dementia?

50 - 60 years Signup and view all the answers

Involves the MAPT gene on chromosome ______.

17 Signup and view all the answers

Match the following types of dementia with their characteristics:

Frontotemporal Dementia = 70% sporadic, young onset (50-60 years) Diffuse Lewy Body Dementia = 2nd most common cause of dementia Alzheimer's Disease = 90-95% sporadic Progressive Supranuclear Palsy = A tauopathy Signup and view all the answers

What is the main genetic mutation associated with CADASIL?

NOTCH 3 Signup and view all the answers

Normal Pressure Hydrocephalus (NPH) is characterized by ventriculomegaly without atrophy.

True Signup and view all the answers

List one common clinical feature of Normal Pressure Hydrocephalus.

Gait apraxia or urinary incontinence or dementia Signup and view all the answers

The most common inherited vascular dementia is ______.

CADASIL Signup and view all the answers

Match the following features with their corresponding condition:

Aura + migraine + dementia + stroke = CADASIL Gait apraxia and urinary incontinence = NPH Occlusive Hydrocephalus = Aqueductal stenosis Idiopathic, familial, congenital, acquired = NPH Etiology Signup and view all the answers

Which of the following nuclei is NOT part of the Basal Ganglia?

Hippocampus Signup and view all the answers

The Basal Ganglia are exclusively responsible for cognitive activities.

False Signup and view all the answers

Name one function of the Basal Ganglia.

Complex motor activity Signup and view all the answers

The _____ nucleus is known to have an internal and external section in the Basal Ganglia.

Globus Pallidus Signup and view all the answers

Match the following functions with the appropriate components of the Basal Ganglia:

Caudate nucleus = Cognitive part of motor activity Putamen = Complex motor activity Subthalamic nucleus = Involvement in movement regulation Substantia nigra = Dopamine production Signup and view all the answers

What is a key characteristic of cognitive impairment in Dementia with Lewy Bodies (DLB)?

Precedes or occurs within 1 year of motor manifestations Signup and view all the answers

In Parkinson's disease, visual hallucinations and fluctuating alertness are common symptoms.

False Signup and view all the answers

What substance is primarily found in Lewy Bodies?

α-synuclein Signup and view all the answers

A common effect of antipsychotic treatment in Dementia with Lewy Bodies is that it _____ symptoms.

worsens Signup and view all the answers

Match the following symptoms with their corresponding condition:

Tremors = Parkinson's Disease Rapidly progressive dementia = DLB Dementia Uncommon visual hallucinations = DLB Dementia Bilateral axial rigidity = DLB Dementia Signup and view all the answers

What is the most significant risk factor for Binswanger Disease?

Hypertension Signup and view all the answers

Cerebral Amyloid Angiopathy is characterized by Aβ40 protein deposition and is commonly seen in the elderly.

True Signup and view all the answers

What type of infarct is associated with Binswanger Disease?

Lacunar infarct Signup and view all the answers

Within 3 months of a stroke, the onset of _____ is often observed.

dementia Signup and view all the answers

Match the clinical features with the affected fibres in Binswanger Disease:

Corticobulbar tract = Pseudobulbar palsy and gait disturbances Corticospinal tract = Gait disturbances and falls Fibres from paracentral lobule = Urinary abnormalities and personality changes Corticostriate fibres = Urinary abnormalities and personality changes Signup and view all the answers

Which type of dementia is characterized by spongiform changes in the cerebral cortex?

CJD Signup and view all the answers

Rapidly progressive dementia is a common feature of prion diseases.

True Signup and view all the answers

What protein is associated with Creutzfeldt-Jakob disease?

PrPsc Signup and view all the answers

In large vessel disease, the most common infarct site is the __________ PCA lesion.

B/1 Signup and view all the answers

Match the type of dementia with its associated protein:

Alzheimer's = αβ Frontotemporal dementia (FTD) = Tau Dementia with Lewy Bodies (DLB) = α-synuclein Creutzfeldt-Jakob disease (CJD) = PrPsc Signup and view all the answers

Which type of rigidity is characterized by both rigidity and tremor at the wrist in Parkinson's Disease?

Cogwheel rigidity Signup and view all the answers

Patients with Parkinson's Disease typically exhibit increased blinking.

False Signup and view all the answers

What gait pattern is described as narrow-based with short quick steps and freezing in between?

Festinant gait Signup and view all the answers

In Parkinson's Disease, the absence of the ______ sign on an MRI may indicate certain changes in the midbrain.

swallow tail Signup and view all the answers

Match the symptoms of Parkinson's Disease with their descriptions:

Bradykinesia = Slowness of movement Hypophonia = Reduced voice volume Hypomimia = Minimal facial expression Froment's sign = Activity-induced increase in rigidity Signup and view all the answers

Which type of dementia is characterized by severe memory impairment and normal cognitive & motor speed?

Subcortical dementia Signup and view all the answers

Cortical dementia is associated with highly impaired coordination.

False Signup and view all the answers

Name one example of a subcortical dementia.

Diffuse Lewy Body Dementia (DLB) Signup and view all the answers

In cortical dementia, the affected regions include the ______ ganglia.

basal Signup and view all the answers

Match the following symptoms to their corresponding type of dementia:

Severe memory impairment = Subcortical dementia Impaired coordination = Cortical dementia Depressed mood = Subcortical dementia Slow cognitive speed = Cortical dementia Signup and view all the answers

Which of the following symptoms is less severe in cortical dementia compared to subcortical dementia?

Memory impairment Signup and view all the answers

Agnosia is a common symptom of both subcortical and cortical dementia.

False Signup and view all the answers

The primary pathology in prion diseases involves the formation of ______ proteins.

infectious Signup and view all the answers

What type of tremor is predominantly seen in Parkinson's disease?

At rest tremor Signup and view all the answers

Essential tremor is usually asymmetric in its distribution.

False Signup and view all the answers

What medication class is typically used to alleviate tremors in Parkinson's disease?

Dopamine agonists Signup and view all the answers

In essential tremor, writing is typically characterized as _____ and tremulous.

large Signup and view all the answers

Match the following characteristics to either Parkinson's disease tremor or essential tremor:

Asymmetric = Parkinson's Disease Tremor Stable or slowly progressive = Essential Tremor Body parts affected: hands, head, voice = Essential Tremor Present extrapyramidal signs = Parkinson's Disease Tremor Signup and view all the answers

Study Notes

Frontotemporal Dementia (Pick's Disease)

Occurs in 70% of cases spontaneously
Onset typically occurs between 50-60 years old
Characterised by rapid progression
Pathology involves the MAPT gene on chromosome 17
Protein Tau becomes hyperphosphorylated
Other proteins associated with the disease are Fus
Bilateral atrophy of the prefrontal cortex
Most common type is Behavioural Variant
Symptoms include Loss of Social Embarrassment, Dysfunction of Social and Emotional Systems
Apathy, Overeating, Impaired Planning and Judgement also frequently occur
Memory is relatively preserved
Temporar lobe involvement results in Increased Oral Behavior
Hyperphosphorylated Tau is a characteristic of both Alzheimer's and Pick's disease

Diffuse Lewy Body Dementia

Second most common cause of Dementia
Associated with Parkinson-Plus and Atypical Parkinson's Syndrome
Parkinson-Plus syndrome involves "Tau"pathies, specifically Progressive supranuclear palsy, Corticobasal degeneration
"a synuclein'-opathies like Multiple system atrophy and Diffuse Lewy Body dementia are also linked
Diagnosis may be related to the presence of certain proteins in the brain
Time Stamps of the video on this topic are 00:00:27 and 00:07:10

Direct and Indirect Pathways

All input from the Cortex to the Striatum
All output goes through the Globus Pallidus Internal (GPi)
The Subthalamus is the only excitatory nucleus in the Basal Ganglia
The Nigrostriatal Pathway connects the Substantia Nigra (SN) to the Corpus Striatum
Via D1 receptors, the direct pathway is activated
The indirect pathway is inhibited via D2 receptors

CADASIL

Cerebral autosomal dominant arteriopathy with small vessel ischemic changes, leukoencephalopathy
Also referred to as CADASIL with stroke and ischemic leukoencephalopathy
Most common inherited vascular dementia
Characterized by a NOTCH 3 mutation
Presentation includes aura + migraine + dementia + stroke

Normal Pressure Hydrocephalus (NPH)

Hydrocephalus

Occlusive (Non-communicating) Hydrocephalus is caused by Aqueductal Stenosis
Non-occlusive (Communicating) Hydrocephalus is caused by increased CSF production or decreased CSF absorption

NPH

Obtuse interventricular angle denotes atrophy
Characterised by an adsorption defect and outflow resistance of CSF, leading to Ventriculomegaly
Atrophy does not occur
Symptoms progress over weeks to months
Gait apraxia (magnetic foot), urinary incontinence, and subcortical dementia are abnormalities commonly observed
Normal CSF pressure (~20 ml/day produced)
Treatment involves Shunting, with good prognosis if effective

NPH Etiology

Most cases are idiopathic
Other etiologies include: Familial, Congenital, and Acquired (Trauma, SAH)

Basal Ganglia (BG)

Gross Anatomy

Includes the following nuclei:
- Caudate nucleus (CN)
- Putamen
- Globus Pallidus (GP)
- Subthalamic nucleus (STN)
- Substantia nigra (SN)
- Corpus Striatum
- Lenticular Nucleus

Physiology

Functions include:
- Complex motor activity
- Initiation and scaling of movement
- Cognitive aspect of motor activity
- Activity set for movement (Planning, programming & initiation)

Common Features of Prion Diseases

Young onset dementia
Rapidly progressive dementia
No immune response
Examples include: Creutzfeldt-Jakob disease (CJD), Familial fatal insomnia, Kuru, Gerstmann-Straussler-Scheinker disease

CJD

No immune response/inflammation
Long incubation period
Pathology reveals Spongiform changes in the cerebral cortex and Basal ganglia hyperintensities
Symptoms include dementia + myoclonus

Investigations for CJD

EEG shows low voltage background, high voltage sharp wave activity
CSF is normal
Brain biopsy is required for diagnosis confirmation
Flupirtine maleate can be used as treatment (centrally acting non-opioid analgesic)

Vascular Dementia

Large vessel disease (Post-CVA dementia) and small vessel disease
Large vessel disease, most common infarct site is Bilateral Posterior Cerebral Artery (PCA) lesion
Criteria include:
- Dementia
- Cerebrovascular disease, particularly multi-infarct state with "strategic territory" infarct (infarcts in areas that lead to dementia)

Lewy Bodies

Intraneuronal cytoplasmic inclusions
Composed of alpha-synuclein
Alpha-synuclein-opathies

DLB Dementia vs Parkinson's Disease

DLB Dementia
- Cognitive impairment precedes/ within 1 year of motor manifestations.
- Shows predominantly rapid progressive dementia.
- Visual hallucinations and fluctuating alertness precede onset of motor symptoms
- Tremors are uncommon
- Bilateral axial rigidity is present (Rocket sign +)
- Gait abnormalities are common
- Antipsychotics worsen symptoms (due to dopamine receptor inhibition)
- L-dopa does not improve symptoms
- No specific treatment available
Parkinson's Disease
- Cognitive impairment occurs after 4–5 years of motor manifestations
- Visual hallucinations are common
- Tremors are common
- Rigidity is common
- Gait abnormalities are common but are asymmetrical
- Antipsychotics have uncommon effects
- L-dopa improves symptoms
- Treatment includes L-dopa, deep brain stimulation
Falling immediately backward after attempting to get up from a chair is characteristic of both conditions.

Binswanger Disease

Most important risk factor is Hypertension
Characterized by Lacunar infarct
Pathology involves Lipohyalinotic infarct affecting penetrating vessels (size: 30 - 300 μm)
MRI shows White matter hyperintensities in elderly

Cerebral Amyloid Angiopathy

Aβ40 protein deposition
Found in elderly individuals
Associated with Microhemorrhages

Relationship between Dementia and Stroke

Onset of dementia within 3 months of stroke
Stepwise decline in cognitive function

Clinical Features (Similar to Vascular Parkinson's)

Corticobulbar tract involvement causes Pseudobulbar palsy, gait disturbances & falls, gait apraxia and the Magnetic/ignition foot phenomenon (feet "stuck" to floor)
Corticospinal tract involvement (affects lower limb fibers close to the ventricle) causes Gait disturbances & falls, gait apraxia and the Magnetic/ignition foot phenomenon
Fibers from the paracentral lobule are associated with Urinary abnormalities and Personality changes
Corticostriate fibers (Fibres from PFC to striatum) are associated with Urinary abnormalities and Personality changes

Subcortical v/s Cortical Dementia

Cortical Dementia
- Includes Alzheimer's and Frontotemporal dementia (FTD)
Subcortical Dementia
- Includes Diffuse Lewy Body Dementia (DLB), Progressive Supranuclear Palsy (PSP), Normal Pressure Hydrocephalus (NPH), and Binswanger disease

Affected Regions

Feature	Subcortical Dementia	Cortical Dementia
Affected regions	Hippocampus, medial temporal lobe	Basal ganglia; Thalamus; Subcortical white matter; Corticospinal fibres; Corticobulbar fibres

Symptoms

Symptom	Subcortical Dementia (Severity)	Cortical Dementia (Severity)
Memory Impairment	Severe (+)	Less severe (-)
Apraxia	Superior parietal lobe lesion	-
Agnosia	Association areas lesion	-
Acalculia	Angular gyrus lesion	-
Language	-	-
Visuo-spatial defect	-	-
Personality	Early dysphasia; more severe; indifferent	-
Mood	Depressed (Subcortical > Cortical)	-
Coordination	Normal	Impaired
Cognitive & motor speed	Normal	Slow
Abnormal movements	Rare	Common
Extrapyramidal symptom	-	-

Prion Diseases
- Prions are infectious proteins with no nucleic acid.
- Can be genetic or sporadic
- Pathology involves Beta-pleated PrPsc protein, leading to Spongiform degeneration of the cortex and Neuronal loss

Parkinson's Disease

Symptoms

Hypertonia
- Two types: Cogwheel rigidity (rigidity + tremor) and lead pipe rigidity
- Froment's sign is activity-induced increase in contralateral rigidity
Akinesia/Bradykinesia
- Bradyphrenia, reduced arm swinging, flexion hypertonia, short quick steps with freezing in between, festinant gait, micrographia, hypomimia, hypophonia, reduced blinking
- Glabellar tap sign is positive
Atypical PD
- Bilateral axial rigidity, difficulty turning in bed/rising from a chair (wheelchair sign)
Non-Parkinson's lesions with hypokinesia, specifically Hypothyroidism
Postural Instability
- Unsteadiness and falls
- Pull test: Patient falls backward

Investigation

Clinical diagnosis
MRI:
- Hyperintensities bilaterally in grey matter surrounded by hypointense red nuclei and crural fibres at the midbrain level
- Swallow tail sign is absent (Swallow tail sign is present due to SN)

Additional Notes

PD patients can also experience sensory symptoms (pain, anosmia), neuropsychiatric symptoms (depression > dementia), and gastrointestinal symptoms (dysphagia)

Comparison of Parkinson's Disease Tremor and Essential Tremor

Characteristics	Parkinson's Disease Tremor	Essential Tremor
Tremor	At rest +/- reemergent tremor	Postural tremor
Frequency	4-6 Hz	5-12 Hz
Distribution	Asymmetric	Mostly symmetric
Body parts affected	Hands ± legs	Hands, head, voice
Writing	Small (micrographia)	Large and tremulous
Course	Progressive	Stable or slowly progressive
Family history	uncommon (1%)	Present
Extrapyramidal signs (bradykinesia, rigidity, and loss of postural reflex)	Present	Absent
Relieving factors	Levodopa, dopamine agonists, anticholinergics	Alcohol, propranolol, primidone, topiramate, gabapentin, clonazepam
Usual site for surgical treatment with deep brain stimulation	Subthalamic nucleus or globus pallidus interna	Ventral intermediate thalamus

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Description

This quiz covers key features of Frontotemporal Dementia (Pick's Disease) and Diffuse Lewy Body Dementia. Learn about their symptoms, pathologies, and genetic associations. Test your knowledge on dementia types and their progression.