cortical-basal ganglionic degeneration; corticobasal degeneration

Epidemiology

• rare
• age of onset 50-70 years

Pathology

• aberrations in tau protein: abnormal staining in neurons & astrocytic processes
• frontal/parietal atrophy
• cortical cell loss
• swollen, achromatic neurons throughout the cerebrum, most numerous in frontal regions
• gliosis
• degeneration of
  • basal ganglia
  • thalamus
  • midbrain
  • locus ceruleus
• rare neuronal plaques
• rare neurofibrillary tangles
• decrease in blood flow to the left hemisphere, especially the parietal & premotor areas (ideomotor apraxia)
• neuronal inclusions?

Clinical manifestations

• pronounced asymmetric rigidity
• ideomotor apraxia
• akinesia
• cortical sensory changes - sensory loss
• alien-limb phenomenon
• myoclonus, limb dystonia (fixed dystonia)
• stimulus sensitive (reflex) myoclonus
• disequilibrium
• dysarthria
• supranuclear gaze palsy
• dementia (common)
  • slowed processing speed
  • impaired working memory
  • impaired executive function
• action tremor
• pyramidal tract signs
• blepharospasm
• aphasia uncommon
• faster progression than Parkinson's disease
• visual hallucinations uncommon

Radiology

• MRI of brain
  • asymmetric cortical atrophy involving posterior frontal lobes & parietal lobes

Differential diagnosis

• frontotemporal dementia
  • sometimes clinically indistinguishable
  • considered by some a subtype of frontotemporal dementia
• amyotrophic lateral sclerosis
  • distinguished by muscle weakness & upper motor neuron signs
  • cognition generally preserved

Management

• generally no response to levodopa/carbidopa (Sinemet)
• acetylcholinesterase inhibitors may be useful for cognitive impairment
• SSRI's may be useful for depression
• avoid neuroleptics

More general terms

• parkinson plus syndrome

Additional terms

• corticobasal syndrome (CBS)
• tauopathy

Patient information

cortical-basal ganglionic degeneration patient information