AIM STEP 10
Student Memory Support
Huntington Disease, Spinocerebellar Ataxias, Motor Neuron Disease and Friedreich Ataxia
4th Year MBBS • Neuroscience • High-yield memory reinforcement and last-minute revision
1. High-Yield Flashcards
Tap each question to reveal the answer.
Which genetic abnormality causes Huntington disease?
CAG trinucleotide repeat expansion in the HTT gene on chromosome 4.
Which basal ganglia structures show marked atrophy in Huntington disease?
The caudate nucleus and putamen.
What clinical triad is characteristic of Huntington disease?
Chorea, behavioral or psychiatric change, and progressive cognitive decline.
What does anticipation mean in Huntington disease?
Earlier onset or greater severity in successive generations due to repeat expansion.
What is the central clinical pattern of spinocerebellar ataxias?
Progressive cerebellar dysfunction with gait ataxia, limb incoordination and dysarthria.
Which motor neuron disease combines upper and lower motor neuron signs?
Amyotrophic lateral sclerosis.
Which clinical signs indicate lower motor neuron involvement?
Weakness, muscle wasting, fasciculations and reduced tone or reflexes.
Which signs indicate upper motor neuron involvement in MND?
Spasticity, increased tone, brisk reflexes and extensor plantar responses.
Which pathological inclusions are classically associated with ALS?
Bunina bodies; abnormal TDP-43 accumulation is also important in many cases.
Which established drug may modestly slow progression in ALS?
Riluzole.
What major supportive problems must be anticipated in progressive MND?
Swallowing, nutrition, communication and respiratory impairment.
Which protein is deficient in Friedreich ataxia?
Frataxin.
Which sensory modalities are characteristically impaired in Friedreich ataxia?
Vibration sense and joint-position sense.
Which important systemic association should be remembered in Friedreich ataxia?
Cardiomyopathy; abnormal glucose metabolism may also occur.
2. Mnemonics
Mnemonic Title
Huntington Clinical Triad
Mnemonic Word
CBC
Meaning
Chorea → Behavioral change → Cognitive decline.
Mnemonic Title
ALS Mixed Motor Pattern
Mnemonic Word
WASH
Meaning
Wasting + fasciculations → LMN; Spasticity + Hyperreflexia → UMN.
Mnemonic Title
Friedreich Ataxia Pattern
Mnemonic Word
ASP
Meaning
Ataxia → Sensory loss → Pyramidal signs.
3. Memory Tables
Motor Neuron Disease — Pattern Recognition
| Type | Predominant System | Key Pattern |
|---|---|---|
| ALS | UMN + LMN | Wasting/fasciculations with spasticity/hyperreflexia |
| Progressive muscular atrophy | LMN | Weakness, wasting and fasciculations |
| Primary lateral sclerosis | UMN | Spasticity and brisk reflexes |
| Progressive bulbar palsy | Bulbar motor neurons | Dysarthria and dysphagia |
4. Rapid Revision Points — Last-Minute Revision
Must Remember:
- Huntington disease is an autosomal dominant HTT CAG-repeat disorder.
- Striatal degeneration, especially caudate and putamen, underlies the movement disorder.
- Spinocerebellar ataxias produce progressive gait and limb incoordination with dysarthria.
- ALS combines upper and lower motor neuron signs in different regions.
- Anterior horn-cell loss produces denervation, wasting and fasciculations.
- Corticospinal degeneration produces spasticity, hyperreflexia and extensor plantar responses.
- Marked sensory loss is not a dominant feature of typical motor neuron disease.
- Bulbar involvement causes dysarthria and dysphagia and increases aspiration risk.
- Friedreich ataxia combines cerebellar, sensory and pyramidal abnormalities.
- Cardiac, orthopedic and rehabilitation needs are important in long-term Friedreich ataxia care.
KMU Exam Trap: Friedreich ataxia can show reduced tendon reflexes together with extensor plantar responses because different neural pathways are affected simultaneously.
5. Clinical Memory Hooks
Adult with chorea + personality change + cognitive decline → think striatal degeneration in Huntington disease.
Wasting + fasciculations + brisk reflexes → combined LMN and UMN involvement → ALS pattern.
Progressive gait ataxia + dysmetria + intention tremor → cerebellar pathway dysfunction.
Young patient with ataxia + loss of position sense + extensor plantars → mixed cerebellar, sensory and pyramidal involvement in Friedreich ataxia.
6. Starred High-Yield Exam Points
- ⭐ Huntington disease: HTT CAG expansion → striatal degeneration → chorea.
- ⭐ Caudate atrophy is a hallmark morphological feature of Huntington disease.
- ⭐ ALS: simultaneous UMN and LMN findings are the key clinical pattern.
- ⭐ Bunina bodies and TDP-43 pathology are important ALS pathology clues.
- ⭐ Riluzole is an established disease-modifying treatment for ALS.
- ⭐ Friedreich ataxia: ataxia + proprioceptive loss + pyramidal signs, with cardiomyopathy as an important systemic association.