CBD and MSA

Question 1

CBD vs. CBS

Answer 1

CBD is a pathologic diagnosis with 4 clinical phenotypes
1. CBS
2. Frontal behavioural spatial syndrome
3. Nonfluent PPA
4. PSP syndrome

Question 2

What is the pathology of CBD?

Answer 2

Tau immunoreactive lesions, in white and grey matter
- Astrocytic plaques
- Thread like lesions

Loss of neurons in focal cortical regions and substantia nigra

Question 3

What is the cognitive profile of CBD?

Answer 3

1. Executive dysfunction
2. Non fluent progressive aphasia
3. Ideomotor apraxia (impaired ability to perform skilled gesture with limb)
4. Limb kinetic apraxia (loss of hand/finger dexterity)
5. Visuospatial dysfunction

Question 4

What is the diagnostic criteria for probable CBS?

Answer 4

1. Asymmetric
2. At least 2 of:
   a. Limb rigidity or akinesia
   b. Limb dystonia
   c. Limb myoclonus
3. Plus 2 of:
   a. Orobuccal or limb apraxia
   b. Cortical sensory deficit
   c. Alien limb phenomena

Question 5

What is the treatment for CBD?

Answer 5

Symptom management
- Baclofen, anticholinergics for rigidity/tone
- Clonazepam for myoclonus
- Botulinum

*Poorly responsive to LD
*Chei and memantine not helpful

Question 6

What are the diagnostic criteria for clinically established MSA?

Answer 6

Sporadic, progressive adult onset disease (>30 yo)

Core Clinical Features
1. Autonomic dysfunction (at least 1 of)
a. Unexplained voiding difficulties (PVR 100 cc+)
b. Unexplained urinary urge incontinence
c. Neurogenic OH
At least 1 of:
2. Poor LD responsive parkinsonism
3. Cerebellar syndrome (min 2 of gait ataxia, limb ataxia, cerebellar dysarthria, oculomotor features)

Supportive features - at least 2
MRI marker - at least 1
Absence of exclusion criteria

Question 7

What are the supportive features of MSA?

Answer 7

Motor
- Rapid progression within 3 yrs motor onset
- Mod-sev postural instability within 3 yrs
- Craniocervical dystonia induced or exacerbated by LD in absence of limb dyskinesia
- Sev speech impairment within 3 yrs
- Sev dysphagia within 3 yrs
- Unexplained Babinski
- Jerky myoclonic postural or kinetic tremor
- Postural deformities

Non motor
- Stridor
- Inspiratory signs
- Cold discoloured hands and feet
- ED
- Pathologic laughter/crying

Question 8

What are the MRI markers of MSA?

Answer 8

MSA-P
- Atrophy of putamen, middle cerebellar peduncle pons, cerebellum
- Hot cross bun sign
- Inc diffusivity of putamen, middle cerebellar peduncle

MSA-C
- Atrophy of putamen and infratentorial structures
- Hot cross bun sign
- Inc diffusivity of putamen

Question 9

Key exclusion criteria for MSA

Answer 9

Dementia according to DSM-V within 3 years of onset

Question 10

Prodromal premotor phase of MSA features

Answer 10

1. Sexual dysfunction
2. Urinary urge incontinence or retention
3. OHOTN
4. Inspiratory stridor
5. REM SBD

Question 11

What are the two subtypes of MSA?

Answer 11

1. Parkinsonism - slow movements, rigidity, tendency to fall
2. Cerebellar - wide gait, uncoordinated limb movements, action tremor, nystagmus

Question 12

What are the non-motor features of MSA?

Answer 12

1. Early and severe autonomic failure
2. GU - ED, urinary dysfunction
3. Cardiac - sev OH, no reflex tachycardia
4. Respiratory - stridor
5. Cognitive - frontal lobe, attention, emotional outburst, depression
6. Disabling pain

Question 13

Management of motor features of MSA

Answer 13

MSA-P = Levodopa, amantadine
Botulinum
Clonazepam
Neurorehab

Question 14

What is the pathophysiology of MSA?

Answer 14

Alpha synucleinopathy
Degeneration of striatonigral and olivopontocerebellar structures