# Clinical Cases: Cerebellum ## Case 1: Cerebellar Stroke with Herniation Risk ### Patient Presentation **Demographics:** 72-year-old male **Chief Complaint:** Sudden severe dizziness, vomiting, and inability to walk **History of Present Illness:** A 72-year-old man with a history of hypertension and atrial fibrillation (on aspirin, not anticoagulated) suddenly developed severe vertigo and vomiting while getting out of bed. He is unable to stand or walk without falling. He describes the room as spinning constantly and has vomited six times. He also reports a severe headache in the back of his head. His wife notes that his speech seems slightly slurred. He denies limb weakness, numbness, or visual changes. **Physical Examination:** - Vital signs: BP 185/105, HR 88 (irregular), RR 18 - General: In distress, vomiting, eyes closed, holding head - Neurological: - Mental status: Alert but drowsy; oriented to person and place - Cranial nerves: Bilateral nystagmus (direction-changing); no facial weakness; gag intact - Motor: 5/5 strength all extremities when tested in bed - Coordination: Severe bilateral limb ataxia - cannot perform finger-to-nose or heel-to-shin - Speech: Dysarthric with scanning quality - Gait: Unable to stand - truncal ataxia and falling backward - Reflexes: 2+ and symmetric; no Babinski **Workup:** - **CT head without contrast:** Hypodensity in right cerebellar hemisphere with early mass effect; compressed fourth ventricle; early hydrocephalus - **CT angiography:** Occluded right posterior inferior cerebellar artery (PICA) - **Repeat CT (4 hours later for worsening drowsiness):** Increased cerebellar edema with complete effacement of fourth ventricle; progressive hydrocephalus **Diagnosis:** Right cerebellar infarct (PICA territory) with obstructive hydrocephalus and impending herniation **Treatment:** - Emergent neurosurgical consultation - External ventricular drain (EVD) placement for hydrocephalus - Suboccipital decompressive craniectomy with resection of infarcted cerebellar tissue - ICU monitoring - ICP monitoring post-operatively - Gradual neurological improvement after surgery - Anticoagulation started after appropriate interval for atrial fibrillation - Intensive physical therapy for ataxia - Walking with walker at discharge; independent ambulation at 3 months with mild residual ataxia **Clinical Pearl:** Cerebellar stroke is a neurosurgical emergency because the posterior fossa is a closed space. Unlike supratentorial strokes, even moderate cerebellar infarcts can cause rapid deterioration from: (1) obstructive hydrocephalus from fourth ventricle compression, and (2) direct brainstem compression as the swollen cerebellum herniates through the foramen magnum (tonsillar herniation) or upward through the tentorial incisura. Warning signs include decreasing level of consciousness, worsening headache, and new brainstem signs. Emergency decompression can be life-saving and often results in good functional outcomes because the brainstem itself may be spared. --- ## Case 2: Friedreich Ataxia ### Patient Presentation **Demographics:** 16-year-old male **Chief Complaint:** Progressive difficulty walking and clumsiness for 3 years **History of Present Illness:** A 16-year-old boy is brought in by his parents for evaluation of gradually worsening balance and coordination. He began having trouble with sports around age 13, initially attributed to "growing pains." Over the past two years, his gait has become progressively unsteady, and he now uses walls for support when walking. He has developed difficulty with handwriting, which has become larger and more irregular. He also reports frequent stumbling on stairs and difficulty buttoning shirts. His speech has become slightly slurred according to his parents. He denies double vision, weakness, or sensory symptoms. Family history reveals a younger sister with similar but milder symptoms. **Physical Examination:** - Vital signs: Normal; cardiac examination reveals systolic murmur - General: Thin adolescent male; kyphoscoliosis noted - Neurological: - Mental status: Normal intelligence and cognition - Cranial nerves: Dysarthria; horizontal nystagmus; no ophthalmoplegia - Motor: Mild distal leg weakness (4/5 ankle dorsiflexion bilaterally); no atrophy - Sensory: Decreased vibration and proprioception at ankles and fingers; normal pain and temperature - Reflexes: ABSENT throughout (areflexia) - Coordination: Severe bilateral limb ataxia; dysmetria on finger-to-nose and heel-to-shin - Gait: Wide-based, ataxic, positive Romberg - Musculoskeletal: High-arched feet (pes cavus); hammer toes; thoracolumbar scoliosis **Workup:** - **MRI brain and spine:** Mild cerebellar atrophy; cervical cord atrophy - **Genetic testing:** Homozygous GAA trinucleotide repeat expansion in FXN gene (frataxin) - 850 repeats (normal <33) - **Echocardiogram:** Concentric left ventricular hypertrophy (hypertrophic cardiomyopathy) - **ECG:** T-wave inversions - **Glucose tolerance test:** Impaired glucose tolerance - **Nerve conduction studies:** Absent sensory responses (sensory neuronopathy); motor studies relatively preserved **Diagnosis:** Friedreich ataxia **Treatment:** - No disease-modifying therapy currently available (clinical trials ongoing) - Cardiology follow-up for hypertrophic cardiomyopathy management - Idebenone (antioxidant) considered for potential cardiac benefit - Physical and occupational therapy - Speech therapy for dysarthria - Orthopedic evaluation for scoliosis and foot deformities - Diabetes screening annually - Genetic counseling for family (autosomal recessive inheritance) - Progressive wheelchair dependence anticipated within 10-15 years **Clinical Pearl:** Friedreich ataxia is the most common inherited ataxia, caused by GAA repeat expansion in the FXN gene encoding frataxin, a mitochondrial protein involved in iron-sulfur cluster assembly. The combination of cerebellar ataxia with ABSENT reflexes (areflexia) is the key clinical clue - most cerebellar disorders cause hyperreflexia, but Friedreich involves the peripheral sensory neurons (dorsal root ganglia) as well, causing a sensory neuropathy. Additional features include cardiomyopathy (the leading cause of death), diabetes, scoliosis, and pes cavus. Age of onset before 25 and areflexia are diagnostic requirements. The sensory ataxia (posterior column involvement) compounds the cerebellar ataxia. --- ## Case 3: Alcoholic Cerebellar Degeneration ### Patient Presentation **Demographics:** 55-year-old male **Chief Complaint:** Difficulty walking for several months **History of Present Illness:** A 55-year-old man is brought in by his brother who reports progressive unsteadiness when walking over the past 6 months. The patient requires support to walk and has fallen multiple times. He also reports numbness and burning in his feet. His speech has become slightly slurred. The patient admits to drinking a pint of vodka daily for the past 20 years and has had poor nutritional intake. He was hospitalized twice for alcohol withdrawal. He denies arm clumsiness or visual problems. **Physical Examination:** - Vital signs: BP 145/88, HR 94 - General: Cachectic, poor hygiene, spider angiomata on chest - Neurological: - Mental status: Mild memory impairment (short-term); otherwise oriented - Cranial nerves: Mild horizontal nystagmus; no ophthalmoplegia; no facial weakness - Motor: Mild proximal weakness (4+/5) upper and lower extremities - Sensory: Decreased sensation to pinprick and vibration in stocking distribution (distal legs) - Reflexes: 2+ in upper extremities; 1+ at knees; absent ankle jerks - Coordination: Legs markedly more ataxic than arms - severe heel-to-shin dysmetria; finger-to-nose relatively preserved - Gait: Wide-based, ataxic gait with truncal instability; cannot tandem walk - Speech: Mildly dysarthric **Workup:** - **MRI brain:** Superior cerebellar vermis atrophy; mild cerebral atrophy - **Vitamin levels:** Thiamine (B1) low; B12 and folate low-normal - **Liver function tests:** Elevated AST, ALT, GGT (alcoholic liver disease pattern) - **Nerve conduction studies:** Length-dependent axonal sensorimotor polyneuropathy - **Blood glucose:** 135 mg/dL (impaired fasting glucose) **Diagnosis:** Alcoholic cerebellar degeneration with peripheral neuropathy **Treatment:** - Thiamine 500 mg IV three times daily for 3-5 days, then oral maintenance - Multivitamin with folate and B12 supplementation - Alcohol cessation counseling and referral to addiction services - Nutritional rehabilitation - Physical therapy for gait training - Gabapentin for neuropathic symptoms - Mild improvement with abstinence and nutrition; gait ataxia largely persistent **Clinical Pearl:** Alcoholic cerebellar degeneration classically affects the superior vermis, causing a characteristic clinical pattern: gait and truncal ataxia is severe while arm coordination is relatively preserved. This contrasts with other cerebellar pathologies that often affect the hemispheres more prominently. The vermis controls midline/axial coordination (gait, trunk), while the hemispheres control appendicular coordination. The pathophysiology involves direct alcohol toxicity and thiamine deficiency. Unlike Wernicke encephalopathy (which can cause similar ataxia but acutely), alcoholic cerebellar degeneration develops insidiously and is often irreversible, though abstinence and thiamine may prevent further progression. --- ## Clinical Image ![Cerebellar atrophy MRI](case_01_image.jpg) **Image Description:** Sagittal T1-weighted MRI of the brain showing cerebellar vermis atrophy with widened folia and enlarged fourth ventricle, characteristic of superior vermian atrophy seen in alcoholic cerebellar degeneration. **Attribution:** Image from Radiopaedia (https://radiopaedia.org/), Creative Commons Attribution-NonCommercial-ShareAlike 3.0 license.