This document discusses Parkinson's disease and parkinsonism. It covers the pathogenesis, classification, clinical features, investigations and imaging findings of Parkinson's disease and other conditions that can cause parkinsonian symptoms. Imaging plays an important role in the diagnosis and differential diagnosis of parkinsonism. Techniques like DAT imaging and MRI can help differentiate Parkinson's disease from other neurodegenerative diseases and conditions.

1. Radiological imaging of parkinsonism.
Dr/ ABD ALLAH NAZEER. MD.

2. Parkinson's disease described by James Parkinson in 1817.
Parkinson’s disease is a chronic neurodegenerative movement
disorder affecting voluntary and emotional movements and most
commonly seen in the elderly, but is also found in the young and
inexorably progresses leading to significant disability.
Average age of onset is 62.5 years.
Men and women affected equally.
Pathogenesis:
Four theories.
Oxidative damage, Mitochondrial dysfunction, enhanced
oxidative stress, proteosomal dysfunction causes cell death.
Environmental toxins, MPTP-Methyl-phenyl tetrahydropyridine,
Mutation in the gene located on chromosome 4.
Genetic predisposition, Mutation in the gene located on
chromosome 4.
Accelerated aging.

4. Classification and Etiology.
Idiopathic Parkinson’s disease
Parkinson-like syndromes
Drug induced parkinsonism
Hypoxia
Tumor
Trauma
Vascular:Multiinfarct
Toxin:Mn, CO, MPTP and cyanide
Post-encephalitic parkinsonism (von Economo’s
encephalitis)
Normal pressure hydrocephalus
Wilson’s disease, Hutington’s disease

5. Medications that can cause parkinsonian
symptoms, but not PD itself, include the following:
Metoclopramide
Domperidone
Reserpine-containing antihypertensives
Neuroleptics
Some evidence also indicates that certain
environmental factors (including smoking and
coffee drinking) may actually have protective
associations.

6. Clinical features of Idiopathic Parkinson’s disease.
Major features
Resting tremor
in hands, arms,
legs, jaw, and
Face.
Bradykinesia
Rigidity- cogwheel
or lead-pipe
Minor features
Bradyphrenia
Speech
abnormalities
Depression
Dysautonomia
Dystonia
Constipation
Hallucinations
Dysphagia

7. Parkinson’s disease Symptomatology.

8. Tremor dominant
Tremor:
 Rest
 Fixed frequency 3-6 Hz
 Not a feature of old age
 Pill-rolling
 Usually starts in one limb, and then
to other limbs
 Rarely starts in lower limbs
 Intermittent for many years
 They usually disappear briefly during
movement and do not occur during
sleep.
• Tremors can also eventually occur in
the head, lips, tongue, and feet. In
younger patients tremor is usually
predominant and often suggests a less
aggressive form of the disease.

9. Rigidity
Striatal hand: Ulnar deviation, MCP flexion, IP extension
Striatal toe: Big toe dorsiflexion
Sitting en bloc: Collapses into a chair on attempting to sit down
Posture
Kyphosis
Flexed elbows, knees and hips
Hands held in front of body
Trunk bent forward
Head bowed

10. Bradykinesia
Slowness of motion (bradykinesia) is one of the classic
symptoms of Parkinson's disease.
Hypomimia- “masked facies”, expressionless face,
blinking
Speech abnormalities-
Hypophonia: soft voice
Aprosody of speech: monotonous and lack of inflection
Tachyphemia: do not separate syllables together,
running words together
Patients may eventually develop a stooped posture and
a slow, shuffling walk. The gait can be erratic and
unsteady.

11. Motor fluctuations
Freezing phenomenon- Sudden, transient inability to
perform active movements, lasting no more than a
few seconds:
Start hesitation
Turn hesitation
Target hesitation
Palilalia (speaking)
Apraxia of eyelid opening
Writing
Kinesia paradoxica-Despite severe rigidity and
bradykinesia, they may rise suddenly and move normally.

12. Festinating gait
Drooling of saliva
Dysphagia
Constipation
Dementia
Depression
Orthostatic
hypotension
Low resting blood
pressure HTN
Normotensive
Sweating
abnormalities-excessive
perspiration
Blepharospasm/
keratitis.

13. Investigations:
The diagnosis is made clinically , as there is no diagnostic test
for Parkinson's disease.
Imaging (CT or MRI) of the brain needed if there are any
features suggestive of pyramidal, cerebellar or autonomic
involvement or the diagnosis is otherwise in dought (e.g to
exclude stroke).
Routine brain imaging is unnecessary in patients with typical
Parkinson’s disease.
Dopamine transporter (DAT) imaging can help to differentiate
patients with Parkinson’s disease from healthy individuals and
patients with essential tremor or drug induced parkinsonism
Structural MRI may be performed to rule out alternative
diagnoses (including other neurodegenerative syndromes and
structural or vascular lesions).

16. T1-weighted MR images show bilateral and symmetrical hyperintensities in the
substantia nigra and cerebral peduncle (A), subthalamic region and hemispheric
white matter (B), and the globus pallidus and putamen (C) in reversal
parkinsonism patient following embolization of intra-hepatic venous shunt.

17. 19-year-old man with secondary parkinsonism (carbon monoxide intoxication) 3 years after
onset, with hyperintense lesion at the globus pallidus and atrophy of the substantia nigra.

18. Parkinsonism due to predominant involvement of substantia nigra in Japanese encephalitis

19. A 64-Year-Old Woman With Bradykinesia and Rigidity in epilepsy.

20. Reversible Acute Parkinsonism and Bilateral Basal Ganglia
Lesions in a Diabetic Uremic Patient.

21. Differential diagnosis of parkinsonism using brain 18F-FP-CIT PET. Brain PET/CT images of 18F-FP-
CIT uptake at level of striatum demonstrate different DAT density in different conditions.
DAT density is decreased in PD patient (B), whereas DAT density is normal in healthy subject
(A) and in patients with drug-induced parkinsonism (C) and essential tremor (D).

22. Color-coded diffusion-weighted MRI and (B) striatal 123I-2β-carbomethoxy-3β-(4-
iodophenyl)-N-(3-iodophenyl) tropane uptake for a healthy individual, a patient with
Parkinson’s disease (PD), and a patient with the atypical parkinsonian syndrome multiple
system atrophy (MSA). The apparent diffusion coefficient (A) is normal in the striatum in
PD but it is raised in MSA (arrows) because of the neuronal loss that targets the putamen.
Dopamine transporter binding (B) is bilaterally reduced in the striata in both PD and MSA.
In PD, the caudate is relatively spared compared with the putamen.

23. White matter lesions in Parkinson disease

24. Fluid-attenuated inversion recovery magnetic resonance imaging sequence of the
brain in a patient with West Nile virus encephalitis with associated parkinsonism
and tremor, displaying signal abnormality in the substantia nigra (short arrow),
the mesial temporal lobe (long arrow) and right posterior thalamus (thick arrow).

27. Dual-Tracer Dopamine Transporter and Perfusion SPECT in Differential
Diagnosis of Parkinsonism Using Template-Based Discriminant Analysis

28. Abnormal signal within the Substantia Nigra in Parkinson Disease.

29. Abnormal signal within the Substantia Nigra in Parkinson Disease.

30. Parkinson Disease with abnormal signal within the pars
impacta at the substantia nigra.

31. Parkinson disease. Hypointensity involves entire putamina diffusely.

32. Left: an axial section through an averaged multispectral image at the level of the
midbrain showing the substantia nigra (SN) in a healthy control participant. Right:
magnified view of the SN in a healthy woman (top) and a woman with Parkinson
disease (PD) (bottom); signal loss in the SN is striking in the PD brain (green arrow).

33. Magnetic Resonance Imaging (MRI) in Parkinson′s Disease.

34. Neurocysticercosis presenting as Parkinsonism.

35. Thank You.