Monday, October 13, 2008

Pearls for Multiple System Atrophy

Neurologist July 2008 14L224-237 authors Bhidayasiri R, Ling H.

MSA encompasses sporadic OPCA (MSA-C) and SND (OPC-P) with predominant Parkinsonism and both types including dysautonomia. Tremor is common but not classic pill rolling tremor. Impotence in men and urge incontinence in women are nearly universal, postural hypotension occurs in 2/3 and syncopal episodes in 15 %. Stridor and respiratory insufficiency may be presenting signs. 29 % respond to levodopa AT SOME POINT.

Red flags suggestive of MSA include early severe autonomic dysfunction, spontaneous or L dopa induced orofacial dyskinesias, which may even resemble risus sardonica in tetanus. Pisa syndrome is a form of axial dystonia, and camptocormia is forward flexion of the trunk. These are not specific and may be seen in PD. Disproportionate anterocollis may occur at any point of the disease, although rare, and botox for this can worsen dysphagia; this is a red flag. So is minipolymyoclonus, which is postural or stimulus sensitive small amplitude nonrhythmic movements of a few fingers or the whole hand. Dysarthria may be diagnostic, with a quivering, croaky strained element "reminiscent of myoclonic speech." (cit Arch Neurol 1996 53:545-548). Nighttime stridor is helpful diagnostically but poor prognostically and may present as laryngeal paresis. Sleep apnea, the "cold hand sign" and emotional incontinence comprise the other red flags.

groupings of "red flags: show six categories  early instability, rapid progression, abnormal postures, bulbar dysfunction, respiratory dysfunction, emotional incontinence.  Presence of two or more categories had high sensitivity (84 % ) and specificity (98%). see Hughes et al.  JNNP 1992; 55:181-184.

Exclusion criteria also are important, including age under 30, positive family history of MSA (PD is "OK"), frank dementia at onset, and eye movement abnormalities suggestive of PSP or CBGD.

The Quinn criteria for possible, probable and definite MSA are reviewed. International Consensus Conference Criteria of the AAN are considered better. See NEJM 2004; 351:912-924 (Case Records of the MGH).

MRI signs include atrophy of the cerebellar vermis, ponsmiddle cerebellar peduncles and lower brainstem. Signal change in the pons may resemble a "hot cross bun" (Catholics may understand this). In MSA-P, patients may have putamenal atrophy, with slit like void signal (black reflecting gliosis) which is sensitive but not specific, but is sensitive and specific if coupled with hyperintense T2 signal in the putamen. For a PD/MSA algorithm, see Arch Neurol 2002; 59:835-842). Onuf's nucleus degenerates which accounts for bladder problems. Pathologic confirmation is made by finding of alpah synuclein positive GCI's composed of misfolded alpah synuclein.

Pearls for treatment include, use of levodopa in many, the benefits of paxil 90 in one trial for motor function, botox of submandibular glands for drooling, and into adductor muscles for stridor, with concerns as above for other uses of botox. PT/OT/ST/ gait training and assistive devices are useful. Treatment of dysautonomic can include, if needed, avoiding large meal, alcohol, straining, certain meds; elastic stockings, bed tilt up at night. Drugs used for orthostasis include florinef, midodrine, desmopressin, octeotride, and eryuthorpoeitin. NGB can be treated with intermittent catheterisation, anticholinergics if detrusor hyperreflexia exists, suprapubic vibration devices, alpha adrenergic receptor antagonists, but NOT surgery. Beware of sildafenil for impotence due to hypotension. Macrogol 3350 for chronic constipation is safe and effective, increasing water content of stools. CPAP, may be needed, tracheostomy may be needed but also may be fatal due to hypercapnia. CPAP mat be contra-indicated if the epiglottis is floppy (Neurology 2011; 76:1841)

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