Spinal cerebrospinal fluid (CSF) leaks are often implicated as the cause of the syndrome of spontaneous intracranial hypotension, but they have rarely been demonstrated radiographically or surgically. The authors reviewed their experience with documented cases of spinal CSF leaks of spontaneous onset in 11 patients including their surgical observations in four of the patients. The mean age of the six women and five men included in the study was 38 years (range 22-51 years). All patients presented with a postural headache; however, most had additional symptoms, including nausea, emesis, sixth cranial-nerve paresis, or local back pain at the level of the CSF leak. All patients underwent indium-111 radionucleotide cisternography or computerized tomographic (CT) myelography. The location of the spontaneous CSF leak was in the cervical spine in two patients, the cervicothoracic junction in three patients, the thoracic spine in five patients, and the lumbar spine in one patient. The false negative rate for radionucleotide cisternography was high (30%). Subdural fluid collections, meningeal enhancement, and downward displacement of the cerebellum, resembling a Chiari I malformation, were commonly found on cranial imaging studies. In most patients, the symptoms resolved in response to supportive measures or an epidural blood patch. Leaking meningeal diverticula were found to be the cause of the CSF leak in four patients who underwent surgery. In three patients these diverticula could be ligated with good result but in one patient an extensive complex of meningeal diverticula was found to be inoperable. Two patients had an unusual body habitus and joint hypermobility, and two other patients had suffered a spontaneous retinal detachment at a young age. In conclusion, spontaneous spinal CSF leaks are uncommon, but they are increasingly recognized as a cause of spontaneous intracranial hypotension. Most spinal CSF leaks are located at the cervicothoracic junction or in the thoracic spine, and they may be associated with meningeal diverticula. The radiographic study of choice is CT myelography. The disease is usually self-limiting, but in selected cases our experience with surgical ligation of leaking meningeal diverticula has been satisfactory. An underlying connective tissue disorder may be present in some patients with a spontaneous spinal CSF leak.

Neuronal oscillations span a wide range of spatial and temporal scales that extend beyond traditional clinical EEG. Recent research suggests that high-frequency oscillations (HFO), in the ripple (80-250 Hz) and fast ripple (250-1000 Hz) frequency range, may be signatures of epileptogenic brain and involved in the generation of seizures. However, most research investigating HFO in humans comes from microwire recordings, whose relationship to standard clinical intracranial EEG (iEEG) has not been explored. In this study iEEG recordings (DC - 9000 Hz) were obtained from human medial temporal lobe using custom depth electrodes containing both microwires and clinical macroelectrodes. Ripple and fast-ripple HFO recorded from both microwires and clinical macroelectrodes were increased in seizure generating brain regions compared to control regions. The distribution of HFO frequencies recorded from the macroelectrodes was concentrated in the ripple frequency range, compared to a broad distribution of HFO frequencies recorded from microwires. The average frequency of ripple HFO recorded from macroelectrodes was lower than that recorded from microwires (143.3 +/- 49.3 Hz versus 116.3 +/- 38.4, Wilcoxon rank sum P<0.0001). Fast-ripple HFO were most often recorded on a single microwire, supporting the hypothesis that fast-ripple HFO are primarily generated by highly localized, sub-millimeter scale neuronal assemblies that are most effectively sampled by microwire electrodes. Future research will address the clinical utility of these recordings for localizing epileptogenic networks and understanding seizure generation.

Aggressive treatment including both surgical decompression and radiation therapy improves the quality of life in patients suffering from symptomatic pituitary metastasis.

A rigorous evaluation of outcomes for tumors such as craniopharyngiomas must consider not only the extent of resection, as judged by postoperative imaging, but also the long-term physical, intellectual, and psychological functioning of the patients.

Focal seizures appear to start abruptly and unpredictably when recorded from volumes of brain probed by clinical intracranial electroencephalograms. To investigate the spatiotemporal scale of focal epilepsy, wide-bandwidth electrophysiological recordings were obtained using clinical macro- and research microelectrodes in patients with epilepsy and control subjects with intractable facial pain. Seizure-like events not detectable on clinical macroelectrodes were observed on isolated microelectrodes. These 'microseizures' were sparsely distributed, more frequent in brain regions that generated seizures, and sporadically evolved into large-scale clinical seizures. Rare microseizures observed in control patients suggest that this phenomenon is ubiquitous, but their density distinguishes normal from epileptic brain. Epileptogenesis may involve the creation of these topographically fractured microdomains and ictogenesis (seizure generation), the dynamics of their interaction and spread.

The likelihood of rupture of unruptured intracranial aneurysms that were less than 10 mm in diameter was exceedingly low among patients in group 1 and was substantially higher among those in group 2. The risk of morbidity and mortality related to surgery greatly exceeded the 7.5-year risk of rupture among patients in group 1 with unruptured intracranial aneurysms smaller than 10 mm in diameter.

We investigated the relationship between preoperative MRI hippocampal volumes and clinical neuropsychological memory test data obtained before and after temporal lobectomy and amygdalohippocampectomy for intractable epilepsy in 44 left (LTL) and 36 right (RTL) temporal lobectomy patients. In LTL patients, the difference (right minus left hippocampal volume) between hippocampal volumes (DHF) was significantly (p < 0.001) correlated (r = 0.61) with postoperative verbal memory change as measured by a delayed memory percent retention score from the Wechsler Memory Scale-Revised, Logical Memory subtest. DHF was also positively associated with postoperative memory for abstract geometric designs in LTL patients (r = 0.49, p < 0.005). Resection of a relatively nonatrophic left hippocampus was associated with poorer verbal and visual memory outcome. In RTL patients, larger right adjusted (for total intracranial volume) hippocampal volume was associated with decline in visual-spatial learning, but not memory, following surgery. MRI hippocampal volume data appear to provide meaningful information in evaluating the risk for memory impairment following temporal lobectomy.

The response to epilepsy surgery during the 1st follow-up year is a reliable indicator of the long-term Engel Class I postoperative outcome. This finding may have important implications for patient counseling and postoperative discontinuation of anticonvulsant medications.