Marianne de Tourtchaninoff

ERPs obtained with the auditory oddball paradigm in coma and altered states of consciousness: clinical relationships, prognostic value, and origin of components.

OBJECTIVE To study the event related potentials (ERPs) in coma and altered states of consciousness, their relationship with the clinical status and coma outcome. METHODS ERPs were recorded with a passive auditory oddball paradigm in 103 patients. Their probability of occurrence and the peak latencies and amplitudes were studied as a function of the Glasgow Coma Score (GCS). Their relationship with outcome was studied in a subset of 83 patients examined within the first 4 days, and expressed in terms of sensitivity, specificity, and negative or positive prognostic values. RESULTS When present, the ERPs to rare stimuli consisted of a fronto-central negativity (N(endog), mean latency: 330 ms) and a fronto-central positivity (P(endog), mean latency: 431 ms) following the exogenous N100-P200 complex. Both their probability of occurrence and their latencies and amplitudes were related with the GCS in anoxic and traumatic comas. The N(endog) and P(endog) had high sensitivity with a negative predictive value of 70% and 100%, respectively, but a low specificity, with a positive predictive value of 44% and 41%, respectively. CONCLUSIONS ERPs can be recorded in some comatose patients and are likely to reflect implicit orienting processes rather than preserved consciousness. Their presence implies a good prognosis but no conclusion can be drawn from their absence.

Somatosensory evoked potential monitoring in carotid surgery. I. Relationships between qualitative SEP alterations and intraoperative events

This paper presents the results of intraoperative median nerve SEP monitoring in 205 successive patients undergoing isolated carotid endarterectomy (CE) (N = 172) or CE followed by coronary bypass (CBP) and/or vascular replacement (VR) (N = 33). The left and right median nerves were alternately stimulated and recordings performed on 4 channels: cervical, ipsi- and contralateral parietal, and frontal. SEPs were qualitatively rated in terms of mild, moderate, or severe ipsilateral, contralateral, or bilateral abnormalities. The SEP abnormalities were subdivided into 5 categories as a function of their relationships with intraoperative events: no alterations (67.3%), early or late SEP alterations after carotid cross-clamping (15.6%), SEP alterations after a drop in blood pressure (occurring outside of or within the cross-clamping period) (15.1%), SEP alterations of a most likely embolic origin (2.4%), SEP changes after head positioning (1%), and SEP changes after a modification of the anesthetic regimen (1.5%). Only moderate to severe SEP alterations occurring soon after carotid cross-clamping justified shunt installation in 16% of the cases. SEP alterations after a drop in blood pressure were reversed merely by restoring blood pressure. The neurological outcome was uneventful in 94.2% of cases. Of the 12 patients who developed neurological sequellae, only one case presented transient sequellae after isolated CE without SEP changes while most cases either had undergone combined CE and CBP and/or VR (6 cases) or had presented SEP alterations of embolic origin (3 cases). We conclude that our system of qualitative rating of SEPs proved very sensitive to intraoperative hemodynamic disturbances or macroembolisms.

Deep EEG Recordings of the Mammillary Body in Epilepsy Patients

Summary:  Purpose: To our knowledge, the epileptic and nonepileptic electroencephalographic (EEG) discharges recorded within the human mammillary body (MB) and mammillothalamic tract (MTT) areas have never been published. Herein, we present the EEG recordings from these structures in patients with refractory epilepsy (RE).

Recurrent seizure and sustained encephalopathy associated with dimethylsulfoxide-preserved stem cell infusion

We report the case of a patient who received two infusions of dimethylsulfoxide (DMSO) cryopreserved autologous peripheral blood progenitor cells (PBPCs) after myeloablative chemotherapy for a relapsing lymphoma. A 49-year-old man presented an episode of tonic-clonic seizure over a few minutes after the start of each infusion and developed a profound and sustained but reversible encephalopathy with coma after the second infusion. The patients neurological condition correlated well with the electrophysiological findings (electroencephalogram and multimodality evoked potentials) and, to a lesser extent, with the radiological abnormalities (magnetic resonance imaging). Severe but reversible neurological complications may occur with the infusion of PBPCs cryopreserved with DMSO.

Evoked potentials investigation of visual dysfunction after methanol poisoning.

OBJECTIVE To present results of electrophysiologic investigations of the visual toxicity observed during the early stage of methanol poisoning. DESIGN Retrospective, clinical study. SETTING A 7-bed intensive care unit in a university hospital. PATIENTS Nineteen patients admitted with a diagnosis of acute methanol poisoning. INTERVENTIONS Visual evoked potentials were obtained within the first 48 hrs after admission; a clinical follow-up examination was performed in 11 patients, and 12 patients were followed up by visual evoked potentials beyond the same delay. Correlations between the occurrence of an optic neuropathy and clinical, biological, and electrophysiological data were studied. MEASUREMENTS AND MAIN RESULTS A significant correlation was found between arterial pH and blood formate concentration (r2 = 0.58, p = .003), between blood formate and bicarbonate concentrations (r2 = 0.36, p = .02), and between delay from ingestion and blood formate concentration (r2 = 0.44, p = .017). Clinical outcome was correlated not only with the bicarbonate (p = .007), formate (p = .018), and methanol (p = .03) concentrations and arterial pH (p = .004) but also with a well-defined electrophysiologic pattern during the acute stage. An index of global cortical functioning > or =3 was associated with death, whereas a global cortical functioning index < or =2 was associated with survival (p = .0058). Moreover, a statistically significant difference in long-term visual impairment was found between the subgroup with abnormal wave III morphology or a global cortical functioning index of 1-2 and the subgroup with normal wave III morphology and a global cortical functioning index <1 (p = .015). Results of the electrophysiologic studies were expressed as retinal dysfunction and optic nerve injury. Five patients had normal findings on electrophysiologic examination. Ten patients had early signs of retinal dysfunction that were fully reversed in the eight patients who were followed. Ten patients had persistent electrophysiologic signs of optic neuropathy. CONCLUSIONS Although reversible retinal dysfunction is evident in the early stage of human methanol poisoning, its absence does not preclude development of optic neuropathy. The occurrence of optic neuropathy and early electrophysiologic data are correlated.

Impact of early hemispherotomy in a case of Ohtahara syndrome with left parieto-occipital megalencephaly.

This report illustrates the usefulness and safety of very early hemispherotomy in an infant with Ohtahara syndrome (OS) secondary to left parieto-occipital megalencephaly. It provides evidence that surgical intervention might provide promising results in selected cases, and that young age is not a contraindication for this type of surgery.

Predicting Spinal Cord Ischemia before Endovascular Thoracoabdominal Aneurysm Repair: Monitoring Somatosensory Evoked Potentials

Purpose: To present a method of predicting spinal cord ischemia before deployment of an endograft in the thoracoabdominal aorta. Case Report: A 76-year-old high-risk patient presented with an aneurysm of the distal thoracic and proximal abdominal aorta. An endovascular treatment was scheduled, but before deployment of the endograft, occlusion of the aneurysmal segment was monitored for 15 minutes using multilevel somatosensory evoked potentials (SEP). An external axillofemoral bypass was necessary during the test period to prevent distal ischemia; transesophageal echocardiography verified the absence of flow inside the aneurysm during occlusion. Because no SEP changes occurred during the 15-minute test, a 20-cm-long endograft was deployed. No postoperative neurological event was encountered, and the aneurysm has remained successfully excluded with shrinkage of the sac diameter by 1 cm at 6 months. Conclusions: An occlusion test to detect spinal cord ischemia before deployment of an endograft could be useful in lowering the risk of paraplegia associated with endovascular treatment of thoracoabdominal aneurysm.

Epileptic discharges in a mammillary body of a patient with refractory epilepsy

Objectives.  To document epileptiform discharges recorded within a mammillary body (MB) of a patient with chronic refractory epilepsy (CRE).

Post-resection electrocorticography has no added value in epilepsy surgery.

Intra-operative electrocorticography (ECoG) has been traditionally used in the surgical management of medically refractory partial epilepsies to identify the limits of the epileptogenic zone. This retrospective study had as goal to evaluate whether tailored surgery based on the presurgical evaluation completed by intra-operative post-resection ECoG improves outcome. We reviewed 94 cases of epilepsy surgery with intra-operative ECoG and determined how many had an ECoG-guided surgical procedure in addition to the initial planned surgery. We also reviewed the presence of specific recurrent ECoG patterns of interictal epileptiform discharges (IED) in the exposed cortical surface, such as: electrographic seizures, bursts, intermittent spike waves, polyspikes or fast rhythms and continuous or quasi-continuous spiking. When performing a post-resection ECoG-tailored surgery, outcome did not improve in lesional or non-lesional epilepsy. Postoperative residual IED did not correlate with a poorer outcome. In our study, the persistence of post-resection IED on ECoG is not correlated with outcome in patients with lesional or non-lesional epilepsy.

Lafora disease: psychiatric manifestations, cognitive decline, and visual hallucinations

A 16-year-old girl presented to our neurology department with gradually deteriorating school results. In her medical history, she had a caesarian section, gastro esophageal reflux, and a tonsillectomy. Both grandmothers, as well as one of her aunts suffered from migraine. At first, school issues were attributed to a difficult familial situation, as her parents recently separated and she had difficulty to cope with the circumstances. She was initially referred to a child psychiatrist. Thereafter, school results did not improve and she barely got through her second year. Finally, she was orientated to technical education. In the summer of 2012, she reported for the first time visual hallucinations, which consisted of colored spots in both visual fields and lasted up to 10 min maximum. There were no similar episodes followed by headache and therefore a visual migraine aura seemed very unlikely. Three months after, she experienced a first tonic-clonic seizure, which was preceded by the earlier reported visual hallucinations. Neurological examination revealed an important bradypsychia. Moreover, she had troubles naming objects and did not fully understand orders. Initial EEG’s performed before admission at our hospital showed occipital spike waves, and therefore, the first hypothesis was a benign focal occipital epilepsy of Gastaut. Patient continued having seizures and levetiracetam was switched to valproic acid. As she still did not experience any benefit of the treatment, the dosage of valproic acid was increased gradually up to maximal levels. Thereafter, oxcarbazepine was associated, but finally her anti-epileptic regimen was switched to a bi-therapy of levetiracetam with carbamazepine. This last drug induced an aggravation of her condition. She became even more encephalopatic and her parents reported she was being clumsier and dropped objects very often at mornings. Retrospectively, it became clear that the patient suffered from non-stimulus sensitive myoclonic seizures—which were aggravated by carbamazepine. They still occurred even though treatment with carbamazepine was interrupted, which indicated that the myoclonic phenomena’s were not merely a side effect of carbamazepine. At last, treatment with levetiracetam was continued and effects on seizure reduction remained stable. At this time, she has daily focal seizures with visual hallucinations, myoclonia about two to three times a week, and only one generalized seizure every 2–3 months. She is still capable of going to a regular school, but on Wednesday and Friday afternoon, she goes back home earlier to rest. The myoclonia is often induced by fatigue and physical effort. Despite the fact that LD is known to be a slow evolving pathology, her actual condition seems to be ‘‘stable.’’ R. El Tahry (&) M. de Tourtchaninoff P. Vrielynck K. Van Rijckevorsel Department of Neurology, Center of Refractory Epilepsy, Cliniques Universitaires Saint-Luc, Universite Catholique de Louvain, Brussels, Belgium e-mail: riem.eltahry@uclouvain.be