Magnetic transcranial brain stimulation and multimodality evoked potentials in an adrenoleukodystrophy patient and members of his family

Long-term effect of bone marrow transplantation in adult-onset adrenoleukodystrophy

We report a long-term outcome of motor function in a patient with adult-onset adrenoleukodystrophy after bone marrow transplantation (BMT). Clinically motor function gradually improved and became almost normal in 2 years after BMT. Serial transcranial magnetic stimulation showed gradual improvement of central motor conduction until 1 year after BMT, and then it became stable. Central motor conduction time and motor threshold were useful for monitoring the central motor function in this patient.

Neurophysiologic follow-up of long-term dietary treatment in adult-onset adrenoleukodystrophy

OBJECTIVE

To monitor the effects of dietary treatment in adult-onset adrenoleukodystrophy (ALD) by means of somatosensory evoked potentials (SEPs) and motor evoked potentials (MEPs).

BACKGROUND

SEPs and MEPs have proved useful in revealing signs of progressively severe, central dying-back axonopathy in early stages of adult-onset ALD.

METHODS

Eight patients with adult-onset ALD underwent clinical examination, brain and spine MRI, and SEP and MEP studies before and after 3 years of Lorenzo's oil dietary therapy.

RESULTS

Before treatment, brain MRI was normal in five patients. Three of these patients had pure spinal SEP abnormalities and in the remaining two patients SEPs showed signs of involvement of both the spinal and cerebral somatosensory tracts. After treatment, the three patients with pure spinal abnormalities showed clinical and neurophysiologic worsening, whereas the two patients with a more advanced stage of disease (exhibited by SEPs) showed substantially unchanged clinical and neurophysiologic features. The patients with abnormal brain MRI at the onset of treatment showed clinical and neurophysiologic worsening.

CONCLUSIONS

Lorenzo's oil therapy had no effect on patients with evidence of inflammatory brain lesions. Moreover, in patients without clear signs of inflammatory damage, this treatment does not modify significantly the natural course of the disease. However, because effective treatments should begin before the onset of severe neurologic symptoms, SEPs and MEPs should be considered to evaluate the effectiveness of other experimental treatments in the patient with a negative brain MRI.

Familial transmission of two independent saccadic abnormalities in schizophrenia

Difficulties with inhibiting inappropriate responses, i.e. disinhibition, and problems with spatial memory are both presumed to be a part of the phenotypic expression of the genetic risk for schizophrenia. Schizophrenic probands are impaired on saccadic eye movement tasks which require (a) response inhibition to prepotent stimuli and (b) generation of an accurate response to a remembered or calculated spatial location, but it is unknown how these deficits are inherited. Sixteen schizophrenic probands, their 32 parents, and two normal control groups completed a delayed oculomotor response and an antisaccade task. The parents with a positive ancestral family history for chronic psychosis (n = 8) were presumed to be more likely than their family history-negative spouses to be genetic carriers for schizophrenia. Probands and their positive family history parents had more failures of response inhibition than did normal control groups. However, it was the probands and their negative family history spouses who demonstrated impaired accuracy of the remembered- or antisaccades. Disinhibition may be closely tied to a specific genetic risk for schizophrenia. However, a second familial factor related to the maintenance or manipulation of spatial information may also contribute to the genetic risk of the full clinical disorder.

Abnormalities of somatosensory and motor evoked potentials in adrenomyeloneuropathy: comparison with magnetic resonance imaging and clinical findings

We studied 6 patients with adrenomyeloneuropathy (AMN) showing mild signs of central nervous system involvement. All patients underwent brain and spinal magnetic resonance imaging (MRI) and somatosensory (SEP) and motor (MEP) evoked potential study. Whereas SEPs and MEPs were abnormal in all patients, only 1 patient showed brain MRI abnormalities; spinal MRI showed hypotrophy without focal abnormalities in 4 of 6 patients. Median nerve SEPs, which were recorded with noncephalic reference montage, revealed delayed or absent scalp P14 far-field potential in all patients and abnormal spinal N13 in 2. Moreover, tibial nerve SEPs revealed abnormalities of the subcortical P30 response in all 4 patients in whom scalp-to-ear recording was employed. These findings strongly suggest that in the early stages of disease neurological dysfunction is localized in the spinal cord, where it is difficult to assess using MRI. However, SEPs and MEPs, which show a typical pattern of abnormality in these patients, could be useful in disclosing signs of long tract involvement and in monitoring treatment.

Transcranial magnetic stimulation in an adrenoleukodystrophy patient

We experienced an 11-year-old boy diagnosed as having adrenoleukodystrophy (ALD), and studied his motor evoked potentials (MEPs) elicited by transcranial magnetic stimulation (TMS). He had intellectual and visual impairment, and MRI revealed high intensity of the parieto-occipital white matter. On evaluation of the long tracts, slight spasticity with equivocal Babinski signs was noted: however, the long tracts appeared intact on MRI, and short latency somatosensory evoked potentials (SSEPs) were completely normal. On TMS delivered through a circular coil, MEPs recorded from the relaxed first dorsal interosseous muscle showed that only the duration was significantly prolonged, which may be due to temporal dispersion of descending volleys in the pyramidal tracts, while the latency was not prolonged. TMS in ALD was considered sensitive and useful for detecting subtle involvement of the long tracts.