Parkinson Disease Flashcards
Cardinal Features of PD
Rest tremor
Rigidity
Bradykinesia
Gait impairment
Additional features Freezing of gait Postural instability Speech difficulty Autonomic disturbances Sensory alterations Mood disorders Sleep dysfunction Cognitive impairment Dementia
Pathologic hallmark of PD
- Degeneration of dopaminergic neurons in the substantia nigra pars compacta
- Reduced striatal dopamine
- Intracytoplasmic proteinaceous inclusions known as Lewy bodies that primarily contain alpha synuclein
Parts of the Basal Ganglia
Striatum (putamen and caudate nucleus)
Subthalamic nucleus
Globus pallidus (interna and externa)
Substantia nigra pars compacta
Gene mutation that is most common cause in familial PD
LRRK2 Gene
Commonly seen in Ashkenazi Jew and North African Berber Arabs
Mutations in Parkin Gene should be considered in patients with onset prior to 40 yo
Multiple System Atrophy manifests as a combination of :
(1) Parkinsonian
(2) Cerebellar
(3) Autonomic Features
Divided into:
(1) predominant parkinsonian
(2) predominant cerebellar
Pathologic characteristics of MSA
Degeneration of SNc, striatum, cerebellum, and inferior olivary nucleus coupled with characteristic glial cytoplasmic inclusions that stain for alpha-synuclein
MRI pathology for MSA
Pathologic iron accumulation in the striatum on T2 weighted scans,
high signal change in the region of the external surface of the putamen (putaminal rim) in MSA-p,
or cerebellar and brain stem atrophy (pontine “hot cross buns” sign in MSA-c
Form of atypical parkinsonism characterised by
Slow ocular saccades
Eyelid apraxia
Restricted eye movements with particular impairment of downard gaze
Progressive supranuclear palsy
MRI pathology in progressive supranuclear palsy
Atrophy of the midbrain with relative preservation of the pons,
“The hummingbird sign” on midsagittal images
Characteristic pathology of PSP
Degeneration of the SNc, striatum, subthalamic nucleus, midline thalamic nuclei and pallidum along with neurofibrillary tangles and inclusions that stain for the tau protein
Manifests as asymmetric dystonic contractions and clumsiness of one hand coupled with cortical sensory disturbances (apraxia, agnosia, focal limb myoclonus or alien limb phenomenon)
Corticobasal ganglionic degeneration
Causes of secondary parkinsonism
Drugs Stroke Tumor Infection Exposure to toxins e.g. Carbon monoxide and manganese
Most common cause of secondary parkinsonism
Dopamine blocking agents such as neuroleptics
Other commonly used drugs include metoclopromide and chlorpromazine
Other drugs: Tetrabenazine Calcium channel blockers (flunnarizine, cinnarizine) Amiodarone Lithium