Atypical Parkinson’s
·
Characterized by early involvement of speech and
gait, absence of resting tremors.
·
Lack of motor asymmetry.
·
Poor or No response to Levodopa.
Pathology:
Neurodegeneration
involves Substantia Nigra Pars Compacta (SNc) (without Lewi bodies).
2 FDG scan:
·
Decreased activity in Globus Pallidus Pars
Interna.
·
Increased activity in Thalamus.
TYPES:
1. 1. MSA (Multi-System Atrophy):
·
Parkinsonism + Cerebellar and Autonomic features (orthostatic
hypotension)
·
Subtypes: MSA – P (Predominant Parkinsonian) and
MSA – C (Predoinant Cerebellar).
·
Pathologically, Degeneration of Substantia Nigra
Pars Compacta, Striatum, Cerebellum and Inferior Olivary Nuclei with
characteristic glial cytoplasmic inclusions (GCIs) that stain positive for
Alpha-Synuclein.
·
MRI T2 Imaging:
o
Iron accumulation in the striatum.
o
In MSA – P: High signal change in the region of
the external surface of the Punctum.
o
In MSA – C: Cerebellar and Brainstem atrophy (the
Pontine “HOT CROSS BUN” sign).
2. 2. PSP (Progressive Supra bulbar Palsy):
·
Characterized by slow ocular saccades, eyelid
apraxia, and restricted vertical eye movements with a particular downward gaze.
·
Symptoms: Hyperextension of the neck with early gait
disturbance and falls.
·
Late features: Speech and swallowing difficulty
and cognitive impairment.
·
Little or NO response to LevoDopa.
·
2 forms:
·
Parkinson form.
·
“Richardson form” (More classical variant)
·
MRI: Characterised by atrophy of the midbrain
images with relative preservation of pons on midsagittal images: “Hummingbird
signs”.
·
Pathology: Denervation of Substantia Nigra Pars
Compacta, Striatum, subthalamic nucleus, midline thalamic nuclei, and pallidum
with neurofibrillary tangles and inclusions which stains for the tau proteins.
3. 3. CBC (Corticobasal Syndrome):
·
Least common.
·
Presentation: Asymmetric dystonic contractions
and clumsiness of one hand couples with cortical sensory disturbances (Apraxia,
agnosis, focal limb myoclonus or alien limb phenomenon).
·
Diagnosis: Both cortical and basal ganglion
features required.
·
MRI: Asymmetric cortical atrophy.
·
Pathology: Achromatic neuronal degeneration with
tau deposits.
________________________________________________________
IF YOU LIKE THE CONTENT, KINDLY SHARE IT AMONY YOUR FRIENDS.
