Cerebellar Disorders

Question 1

Cerebellar Hemorrhage

Answer 1

Most often due to hypertension

Can break into the 4th ventricle ⇒ hydrocephalus

Question 2

Non-Hereditary

Cerebellar Ataxias

Answer 2

• Toxic – including alcohol
  
  • Usually affects vermis and anterior cerebellum ⇒ truncal and gait ataxia
• Tumors – due to effect of tumor itself or causing paraneoplastic syndromes
• Paraneoplastic Syndromes
  
  • Pathogenesis: Auto-Ab against neural tissue
  • Causes cerebellar ataxia

Question 3

Paraneoplastic Syndromes

Clinical Presentation

Answer 3

• Middle-aged to older pt w/ lung, ovarian, lymphatic or breast cancer
• Sx develop over days to weeks and often occur prior to discovery of primary malignancy
• Findings include:
  
  • Ataxia
  • Dysphagia
  • Hypotonia
  • Dysarthria
  • Visual and sleep disturbances
  • Dementia
  • Seizures
  • Sensory loss
  • Vertigo

Question 4

Ataxia-telangiectasia

Pathogenesis

Answer 4

Hereditary cerebellar ataxia

• Autosomal recessive
• Caused by mutations in ATM gene on chromosome 11, which is involved in cell cycle control

Question 5

Ataxia-telangiectasia

Clinical Presentation

Answer 5

Symptom onset occurs in childhood

Signs and sx include:

• Telangiectasias (small, widened blood vessels on the skin)
• Recurrent sinus & pulmonary infections
• Choreoathetosis (involuntary twitching or writhing)
• Intellectual disabilities (30%)
• Neoplasms (hematologic)

Question 6

Abetalipoproteinemia

Pathogenesis

Answer 6

Hereditary cerebellar ataxia

• Autosomal recessive
• Defect of MTTP gene (microsomal triglyceride transfer protein) ⇒ inability to make beta-lipoprotein ⇒ malabsorption of dietary fats and fat-soluble vitamins A, D, E, and K and cholesterol
• Rare (~ 100 reported cases)

Question 7

Abetalipoproteinemia

Clinical Presentation

Answer 7

Symptom onset in childhood

Findings include:

• Failure to thrive
• Diarrhea with steatorrhea
• Ataxia
• Retinitis pigmentosa (loss of vision)

Question 8

Friedreich Ataxia

Pathogenesis

Answer 8

Hereditary cerebellar ataxia

• Autosomal recessive
• Mutation of FXN on chromosome 9 which codes for Frataxin
  
  • Found in mitochondria
  • Appears to help assemble clusters of iron and sulfur molecules critical for the function of many proteins
• Incidence 1 in 50k

Question 9

Friedreich Ataxia

Clinical Presentation

Answer 9

Sx appear between ages 5-15 years

• Gait ataxia ⇒ arms and trunk
• Loss of position sense & vibratory sense in legs
• Areflexia (loss of deep tendon reflexes)
• Scoliosis
• Dysarthria & dysmetria (past-pointing)
• Hearing and vision loss
• Cardiomyopathy
• 20% develop carbohydrate intolerance; 10% develop diabetes
• In contrast to Ataxia-telangiectasia, cognition is unaffected