Absence of memory dysfunction after bilateral mammillary body and mammillothalamic tract electrode implantation: preliminary experience in three patients.

Comment on Acute Korsakoff syndrome following mammillothalamic tract infarctio

Stereotactic ventriculoperitoneal shunting for refractory idiopathic intracranial hypertension.

OBJECTIVE: Recent reports have shown promising short- to medium-term results in patients with refractory idiopathic intracranial hypertension (IIH) treated using the stereotactic ventriculoperitoneal shunting (SVPS) technique. However, the long-term clinical efficacy of this technique remains questionable. This report provides the long-term results of SVPS in treating refractory IIH patients. METHODS: We reviewed the medical charts of nine consecutive patients (mean age, 26.4 yr; range, 4-63 yr) treated using either a frame-based or frameless SVPS technique for IIH. RESULTS: The mean postoperative follow-up period was 44.3 months (range, 6-110 mo). Before shunting procedures were performed, each patient presented with intractable headache, and five patients (55.6%) had mild to moderate visual deficits. The last follow-up assessment showed that after shunting was performed, eight patients (89%) were headache-free. Only one patient had recurrent headache; however, this patient's pain was much less frequent and severe than before the shunting procedure was completed and was concomitant with recent weight increase. Visual deficits were resolved in three patients and remained stable in two who already had optic nerve atrophy before shunting was completed. Twelve SVPS procedures were performed on our patients. Nine shunt revisions were needed in six patients because of infection (n = 5, including two revisions in one patient), valve dysfunction (n = 2), distal obstruction (n = 1), and ventricular catheter malpositioning (n = 1). No patient had proximal catheter obstruction. CONCLUSION: Given the favorable long-term outcome of the SVPS technique for refractory IIH, we are encouraged to apply this procedure on our patients. More invasive approaches should be reserved for patients who have SVPS failure

Subdural motor cortex stimulation for central and peripheral neuropathic pain: a long-term follow-up study in a series of eight patients.

OBJECTIVE: In certain chronic neuropathic pain (CNP) conditions, extradural electrode implantation is preferred to a subdural location for motor cortex stimulation (MCS) therapy, but the rationale for this preference remains debatable. We provide documented long-term results of subdural MCS in CNP. METHODS: Our eight consecutive patients (five men, three women; age range, 45-81 yr) had either central or peripheral CNP. We localized the central sulcus using anatomic landmarks and three-dimensional neuronavigation and by detecting the N20 wave inversion. We then created an elongated craniotomy (3 cm long x 1 cm wide), followed by a linear incision of the dura. An eight-polar plate electrode was slipped in subdurally. We used motor-evoked potentials to choose the optimal electrode position before fixing the electrode to the dura. RESULTS: Six patients had favorable outcomes, and two had poor outcomes at the time of the last assessment (mean, 54 mo; range, 19-69 mo). Three patients experienced five transient complications, each having an episode of partial motor seizure, one that evolved into a secondary generalized seizure. Seizures were related to an abrupt increase in stimulation intensity. Two of these three patients also had hardware infections that required system replacement, with the electrode implanted extradurally at the second implantation in one case because of severe arachnoiditis. This change necessitated a greater intensity and a longer duration of stimulation to deliver a therapeutic effect equivalent to that with subdural MCS. CONCLUSION: In this small series, subdural MCS seemed a tolerable approach in the long term for CNP patients. In addition, subdural MCS provided a therapeutic effect comparable to that obtained with extradural placement

Deep EEG recordings of the mammillary body in epilepsy patients.

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). METHODS: Three men (ages 41-43 years) were enrolled in a clinical trial for deep brain stimulation (DBS) of MB-MTT in RE. Previous evaluations had demonstrated a low likelihood of successful response to medication or resective surgery. DBS macroelectrodes were bilaterally implanted within the MB-MTT under general anesthesia and their location checked by magnetic resonance imaging (MRI). We obtained a surface-depth EEG for a 2- to 4-day period, including monitoring of the cardiorespiratory and mnemonic functions. RESULTS: The background pattern of EEG recorded from MB-MTT was low-amplitude (usually <25 microv for MB and <20 microv for MTT) waves with a variable combination of theta-beta rhythms. In two patients, pseudoperiodic slow spikes were unilaterally recorded with or without clinical signs. For one patient, several focal ictal discharges were recorded in the right MB without scalp EEG changes. CONCLUSIONS: The analysis of our depth EEG revealed that the theta-beta pattern represents the predominant physiologic profile of MB. Paroxysmal epileptiform discharges can be observed in human MB. These data supplement those available from animal observations

Postoperative spinal adhesive arachnoiditis presenting with hydrocephalus and cauda equina syndrome.

To our knowledge, the association between hydrocephalus and postoperative spinal adhesive arachnoiditis (SAA) has never been reported. Herein we describe an unusual case of a 45-year-old man with spinal adhesive arachnoiditis (SAA) who developed delayed-onset hypertensive hydrocephalus and cauda equina syndrome (CES) after multiple low-back surgeries. The patient's clinical presentation, imaging findings, surgical management, and the possible mechanisms are discussed in the light of the present literature

Unusual CT/MR features of putative ligamentum flavum ossification in a North African woman.

To display the unusual spinal CT and MR findings in a 48-year-old North African woman presenting with two adjacent intracanalar mineralized epidural outgrowths exhibiting mature bone organization with "cortical" and "trabecular" areas and pseudoarthritic changes at their interface. An unusual form of ligamentum flavum ossification (LFO) was speculated, of which features are discussed under the light of the available literature

Microsurgical results with large vestibular schwannomas with preservation of facial and cochlear nerve function as the primary aim.

OBJECTIVE: To evaluate our microsurgical results in dealing with vestibular schwannomas (VS) greater than or equal to 30 mm when preservation of cranial nerve function was considered more important than total tumour removal. METHODS: Sixteen consecutive cases were operated on by the same neurosurgeon according to a prospective protocol using intraoperative neuro-monitoring (IONM) based on electromyographic and brain stem auditory evoked potential recordings. Facial nerve function was evaluated on the House-Brackmann Scale and cochlear nerve function on the Gardner-Robertson Scale. Someone not involved in the clinical management of our patients collected all data. RESULTS: Fifteen patients showed facial nerve (FN) function of House-Brackmann grade (HBG) I or II at one year postoperatively and one kept the HBG IV she had preoperatively. Two patients of four maintained a cochlear nerve function of Gardner-Robertson grade (GRG) II. The tumour excision rates were: total, 68.7%; near total, 6.3%; subtotal, 18.7%, and partial, 6.3%. The average follow-up was 55 months (1-106). Three patients underwent radiotherapy later with growth stabilisation and no additional morbidity. CONCLUSION: When dealing with VS greater than or equal to 30 mm, microsurgery guided by IONM, with a rate of total or near-total tumour excision of about 75%, can retain socially acceptable facial nerve function (HBG I or II) in all cases and serviceable hearing (GRG I or II) in two cases out of four. Maintaining serviceable cranial nerve function should take precedence over total tumour excision

Nonsuture dural repair using a patch and fibrin glue after posterior fossa decompression in Chiari I malformation

Objective We describe a new technique of nonsuture dural closure using fibrin glue with graft placed subdurally applied for Chiari I patients treated via extra-arachnoidal posterior fossa decompression procedure (arachnoid preserved intact)