MASA syndrome
Overview
A very rare inherited disorders characterized by mental retardation (M), aphasia (A), shuffling walk (S) and adducted thumbs (A). The symptoms are variable from case to case but mental retardation is a consistent feature
Symptoms
* Mental retardation * Reduced communication ability * Aphasia * Shuffling walk * Thumb flexed towards palm
Causes
* Stroke is the most common cause of aphasia –Sudden onset suggests cerebral embolization from a cardiac (e.g., endocarditis, atrial fibrillation) or carotid artery source –A stuttering onset suggests in situ arterial thrombosis * Less common etiologies include Alzheimer's dementia, postconcussion syndrome, Rasmussen's encephalitis, nonconvulsive status epilepticus, dissociative state, subdural hematoma, trauma, severe hypoglycemia, sedative-hypnotic drug intoxication, sensorineural hearing loss, herpes encephalitis, and tertiary syphilis * Types of aphasias Receptive (Wernicke's) aphasia –Inability to name objects, follow written or spoken commands, and repeat –Verbal (semantic, neologistic) errors are abundant; however, speech is fluent –Localized to the dominant posterior superior temporal lobe * Expressive (Broca's) aphasia –Stuttering, nonfluent speech with literal (phonemic) errors; however, comprehension is preserved –Repetition is poor, but naming is preserved –Associated with hemiparesis –Localized to the inferior lateral dominant frontal lobe * Anomic aphasia –Isolated inability to name a seen object –Localized to the angular gyrus o Conduction aphasia –Isolated inability to repeat –Localized to the arcuate fasiculus (white matter band connecting Wernicke to Broca areas) o Transcortical sensory aphasia –Similar to Wernicke's aphasia, except for preserved repetition –Localized to the superior posterior temporal lobe + Transcortical motor aphasia –Similar to Broca's aphasia, but with preserved repetition, including urinary incontinence, echolalia (aimlessly repeating other's spoken words) –Localized to medial dominant frontal lobe
Diagnosis
1. Is it intermittent? Episodic aphasia, apraxia, or agnosia would suggest epilepsy, transient ischemic attacks, migraine, or hypertensive encephalopathy. 2. Is it acute or gradual in onset? Acute onset of aphasia, apraxia, or agnosia would suggest a cerebral vascular accident, or if there is fever, the onset of a cerebral abscess. It may also mark the onset of acute encephalitis. The gradual onset of aphasia, apraxia, and agnosia would suggest a tumor or other type of space-occupying lesion. 3. Is there associated headache or papilledema? Headaches with aphasia, apraxia, and agnosia might suggest migraine, but one should not forget a brain tumor. Obviously, papilledema is a sign of a space-occupying lesion. 4. Is there significant dementia? The development of dementia along with the aphasia, apraxia, and agnosia suggest Alzheimer's disease, Pick's disease, herpes encephalitis, multiple sclerosis, or Korsakoff's psychosis.
Treatment
* Embolic stroke: Anticoagulation; however, if secondary to endocarditis, do not initiate anticoagulation, because of increased risk of hemorrhage; instead, treat with antibiotics * Thrombotic stroke: Antiplatelet therapy (e.g., aspirin or clopidogrel) and risk factor reduction (e.g., lipid and hypertension therapy) * Viral encephalitis: IV acyclovir for 10–14 days * Dementia: Acetylcholinesterase inhibitors are of variable effectiveness in Alzheimer's disease * Status epilepticus: IV lorazepam and anticonvulsants * Hypoglycemia and other electrolyte abnormalities: Correction of underlying metabolic problem * Dissociative state: Oral or IV benzodiazepines may “break the spell” of psychiatric separation of attention from the environment; ECT may be necessary * Speech therapy is useful to help maintain motivation to improve language function and avoid depression from communication impairment