Tuesday, February 12, 2008

Localization of postictal nose rubbing

Geyer JD, Payne TA, Faught E, et al. Posictal nose rubbing in the diagnosis lateralization and localization of seizures. Neurology 1999; 52: 743-745.

Posticatal nose wipe occurred in 25/50 patients with right TLE and 21/50 patients with left TLE, 90 % with the ipsilateral hand wiping. It occurred in 5/50 patients with frontal epilepsy and not in any patients with generalized epilepsy (0/11) or nonepileptic events (0/100).
Discussion-- author related the nose-wipe to olfactory hallucinations in the aura of patients with TLE and the involvement of the uncus or its connections. About 2 thirds of the patients with postictal nose wiping had tonic stiffening, tonic clonic activity, dystonic posturing, or postictal paresis of the contralateral limb.

Ictal humming and singing

Bartolomei F, McGonigal A, Guye M et al. Clinical and anatomic characteristics of humming and singing in partial epilepsy. Neurology 2007; 69: 490-491.

A French study of musical automatisms in 7/416 epileptics in Marseilles. Humming occurred relatively late during a seizure (mean 23 seconds into one) and always was associated with a loss of consciousness. Patients had right or bilateral hemispheric (temporal) discharge on EEG.

Singing epilepsy was an articulated vocal automatism with musical intonation, with abrupt onset of singing early in the seizure, and complex behavioral changes including euphoric appearance, laughing, gesturing automatisms and dancing like behavior. In 2 cases, this was associated with right frontal seizures originating in the DLF cortex.

Saturday, February 9, 2008

The anatomy of aphasia revisited

Kreisler A, Godefroy O, Delmaire C, et al. Neurology 2000; 54:1117-1123.

The authors investigated 107 patients with a standard aphasia battery and looked at 69 predetermined areas of interest. They found an analysis to identify 67-94 $ of patients.
1. Nonfluent aphasias depended on frontal or putamenal lesions (mutism, low fluency) (IFG to put, or ant centrum semiovale to PUT or IPL
2. Repetition depended on insula-external capsule lesions and posterior internal capsule
3. Comprehension depended on posterior lesions of the temporal gyri,or IFG
4. Phonemic paraphasias depend on external capsule lesions extending to the posterior temporal lobe or internal capsule
5. Verbal paraphasias on temporal or caudate lesions
6. Perseveration on caudate lesions

Notes-- role of supramarginal gyrus and arcuate fasciculus was not confirmed. Syntactic comprehension depends on IFG.

Wednesday, February 6, 2008

Neuropsychological and neurophysiologic effects of carbamazepine and levitiracetam

Meador KJ, Gevins A, Loring DW, et al. Neurology 2007;69:2076-2084.

In the latest installment of the Meador AED experiments on healthy volunteers, using the time tested randomized double blind crosover study on 28 adults, levitiracetam was shown to beat CBZ byhaving less untoward effects than CBZ on all measures that differed.

Details: CBZ mean maintenance doses 564 mg/day, mean serum level 7.5; lev mean dose 2000 mg/day mean level 32. They calculated a standard neuropscyh score but more interestingly, LEV won on subtests of stroop, fatigue, attention, language, memory, dysphoria,l cognition. The placebo or non drug group beat lev on only tiredness and visual symbol digit modalities but beat CBZ on a whole host of measures.

Authors note that the AE'd of LEV behaviorally occur more commonly in learning disabled and those with psychiatric histories.

Monday, February 4, 2008

A French accent after corpus callosum infarct

Hall Da, Anderson CA, Filley Cm et al. Neurology2003; 1551.

A patient with a midcallosal lesion (English) developed a foreign accent syndrome that resembled a native French speaker after this infarct. There was altered intonation, stresses and pauses. The problem remained six months later. The authors attribute this to the involvement of the CC in linguistic and affective prosody. They believe the lesion interrupted bihemispheric networks subserving prosody.

Comment-- an unappreciated callosal syndrome, not in most textbooks.

Differential cognitive and behavioral effects of topiramate and valproate

Meador KJ, Loring DW, Hulihan JF et al. Neurology 2003; 1483-1488.

TPM or VPA was added to CBZ in patients with partial epilepsy. After a 4 week baseline, subjects were titrated to 400 mg/d of TPM, 2250 of VPA or placebo and then maintained while undergoing vigorous test-retest neuropscyh. 62 patients were studied. TPM did slightly worse especially on COWAS (Controlled Oral Word Association Test) and Symbol Digit Modalities Test.

Martin R, Kuzniecky R, Ho S. COgnitive effects of topiramate, gabapentin, and lamotrigine in healthy young adults. Neurology 1999; 52: 321-327.

Among young healthy adults treated with TPM, GPN, LTG for 2 and 4 weeks only the TPM group showed neurocognitive effects especially on measures of attention and word fluency, whereas the other 2 groups had no changes.

Forced collectionism after orbitofrontal damage

Volle E, Beato R, Levy R, Dubois B. Neurology 2002; 58:488-490. Authors describe a patient who collected household electrical appliances folllowng bilateral orbitofrontal and polar prefrontal damage. The collectionism was goal directed and selective but involuntary and irrepressive. In background, the authors put on a spectrum prehensile forced grasping, hoarding behavior and collectionism. In this case the lesion was due to an OF meningioma which was treated surgically. Besides collecting old TV sets , in all rooms of the house, he could stay in the car for hours doing absolutely nothing. Neuro exam was normal. Neuropsych exam (including frontal tests) were normal except "marked inertia." The authors attribute the finding (with homage to L"hermitte) to uninhibited stimulation from parietal cortex that activates a prehension or imitation behavior, due to disruption of parietal and frontal interactions. L"hermitte expressed it as the expression of physical adherence to external stimuli and loss of autonomy of subjects from their environment. Sarazin M (Neurology 1998) described a correlation between collectionism and on PET scans, low metabolism in DLF regions bilaterally.

Hoarding behavior has been described as part of the syndrom after rupture of an ACOM aneurym that are alternately characterized as part of an obcessive compulsive behavior or impulse control disorder (Cohen et al.,Lancet 1999). In degenerative diseases "collectors" are typically hoarders without specific selection.

The authors distinguish collectionism, or "forced colectionism" , prehension, hoarding and compulsive behaviors. Collectionism depends upon 1) adequate motivation and mental representations of specific goals 2) absent severe planning deficit 3) release of a searching behavior .