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Biomedical subjects

John F Kerrigan

Publications and source records attributed to John F Kerrigan.

13 recordsLinked to original sources
PubMed2006

Endoscopic surgery for hypothalamic hamartomas causing medically refractory gelastic epilepsy.

INTRODUCTION: There is increasing evidence that removal or disconnection of hypothalamic hamartomas can lead to seizure control and improvement in behavior. The purpose of this study is to report our experiences with endoscopic removal of these hamartomas. METHODS: This is a prospective review of the early outcome of 44 patients undergoing endoscopic resection utilizing frameless stereotaxis and a micromanipulator. RESULTS: All patients had normal-sized ventricles. Complete removal was possible in 14 patients, 13 of whom were seizure free at follow-up. Four patients suffered complications that have persisted for more than 3 months: One had significant hemiparesis and three had persistent difficulties with short-term memory. Postoperatively, no patient suffered a permanent hormonal deficiency. In one patient who had undergone a previous attempt at transcallosal resection, the procedure was abandoned because of the lack of internal anatomic landmarks. In a second patient, insufficient mass could be removed due to the size of the lesion and the distorted anatomy. Consequently, 1 week later, the patient underwent a transcallosal approach. CONCLUSION: In appropriately selected patients, sessile hypothalamic hamartomas can be removed completely or they can be completely disconnected from the hypothalamus with an acceptable risk. At least a year after surgery is needed to evaluate the efficacy of the procedure in terms of control of seizures and improvements in behavior and emotional ability.

Adolescent↗
PubMed2006

Transcallosal resection of hypothalamic hamartoma for intractable epilepsy.

PURPOSE: To present the results of transcallosal surgical resection of hypothalamic hamartoma (HH) in 26 patients with refractory epilepsy in a prospective outcome study. METHODS: Patients with refractory epilepsy symptomatic to HH were referred for surgical resection of their HH (mean age, 10.0 years; range, 2.1-24.2 years). A transcallosal, interforniceal approach was used to remove and/or disconnect the hamartoma. Volumetry was obtained on pre- and postoperative brain MRI scans to determine percentage of resection. Outcome assessment included determination of postoperative seizure frequencies in comparison to baseline and the incidence of postoperative complications. Postoperative changes in cognitive and behavioral functioning, in comparison to baseline, were elicited by parental report. RESULTS: The average postoperative follow-up interval was 20.3 months (range, 13-28 months). Fourteen (54%) patients were completely seizure free, and nine (35%) had at least a 90% improvement in total seizure frequency. Parents reported postoperative improvement in behavior in 23 (88%) patients and in cognition in 17 (65%) patients. Transient postoperative memory disturbance was seen in 15 (58%) patients, but persisted in only two (8%). Two (8%) patients had persisting endocrine disturbance requiring hormone replacement therapy (diabetes insipidus and hypothyroidism in one each). With univariate analysis, the likelihood of a seizure-free outcome correlated with younger age, shorter lifetime duration of epilepsy, smaller preoperative HH volume, and 100% HH resection. CONCLUSIONS: Refractory epilepsy associated with HH can be safely and effectively treated with surgical resection by a transcallosal, interforniceal approach. Short-term memory deficits appear to be transient for most patients, and family perception of the impact of surgery on cognitive and behavioral domains is favorable. Complete resection yields the best result.

Adolescent↗
PubMed2006

Leukoencephalopathy with bilateral anterior temporal lobe cysts.

Recently, several reports describing patients with a nonprogressive clinical course, increased signal in the cerebral white matter, and cystic changes in the anterior temporal lobes on magnetic resonance imaging (MRI) have appeared. To date, 25 patients with this very distinctive condition have been described. We report four new cases of this newly recognized entity. All have been identified primarily because of the distinctive MRI features consisting of the very unusual anterior temporal lobe cystic changes. The clinical features are characterized by severe, disabling, but nonprogressive mental and motor retardation. Magnetic resonance spectroscopy has shown increased myo-inositol and decreased N-acetylaspartate in the cerebral white matter. This is a distinctive, probably genetic, condition with characteristic neuroimaging and clinical features. In the appropriate clinical situation, the neuroimaging features are diagnostic.

Adolescent↗
PubMed2005

Electrophysiological properties of human hypothalamic hamartomas.

The hypothalamic hamartoma (HH) is a rare developmental malformation often characterized by gelastic seizures, which are usually refractory to medical therapy. The mechanisms of epileptogenesis operative in this subcortical lesion are unknown. In this study, we used standard patch-clamp electrophysiological techniques combined with histochemical approaches to study individual cells from human HH tissue immediately after surgical resection. More than 90% of dissociated HH cells were small (6-9 microm soma) and exhibited immunoreactivity to the neuronal marker NeuN, and to glutamic acid decarboxylase, but not to glial fibrillary acidic protein. Under current-clamp, whole-cell recordings in single dissociated cells or in intact HH slices demonstrated typical neuronal responses to depolarizing and hyperpolarizing current injection. In some cases, HH cells exhibited a "sag-like" membrane potential change during membrane hyperpolarization. Interestingly, most HH cells exhibited robust, spontaneous "pacemaker-like" action potential firing. Under voltage-clamp, dissociated HH cells exhibited functional tetrodotoxin (TTX)-sensitive Na(+) and tetraethylammonium-sensitive K(+) currents. Both GABA and glutamate evoked whole-cell currents, with GABA exhibiting a peak current amplitude 10-fold greater than glutamate. These findings suggest that human HH tissues, associated with gelastic seizures, contained predominantly small GABAergic inhibitory neurons that exhibited intrinsic "pacemaker-like" behavior.

6-Cyano-7-nitroquinoxaline-2,3-dione↗
PubMed2005

The hypothalamic hamartoma: a model of subcortical epileptogenesis and encephalopathy.

Although uncommon, the hypothalamic hamartoma (HH) is often associated with a devastating clinical syndrome, which may include refractory epilepsy, progressive cognitive decline, and deterioration in behavioral and psychiatric functioning. Contrary to conventional thinking which attributed seizure origin to cortical structures, the hamartoma itself has now been firmly established as the site of intrinsic epileptogenesis for the gelastic seizures (i.e., characterized by unusual mirth) peculiar to this disorder. It also appears that the HH contributes to a process of secondary epileptogenesis, with eventual cortical seizure onset of multiple types in some patients. Anticonvulsant medications are known to be poorly effective in this disorder. Treatment, including some innovative approaches to surgical resection, is now targeted directly at the HH itself, with impressive results. Younger patients, in particular, may avoid the deteriorating course described earlier. Access to tissue from larger numbers of patients at single or collaborating centers specializing in HH surgery will allow for research into the fundamental mechanisms producing this little understood disorder. Refractory epilepsy associated with HH is the premier human model for subcortical epilepsy and an excellent model for secondary epileptogenesis and epileptic encephalopathy.

Animals↗
PubMed2005

Successful resection of a hypothalamic hamartoma and a Rathke cleft cyst. Case report.

The authors report the case of a 12-year-old girl with Pallister-Hall syndrome, long-standing refractory, symptomatic epilepsy, mental retardation, and panhypopituitarism in whom two rare, deep midline lesions were detected. She underwent successful transsphenoidal resection of the Rathke cleft cyst and transcallosal resection of the hypothalamic hamartoma within a 4-day period without complications. Neuropathological studies confirmed the neuroimaging diagnoses for the two lesions. The patient has been seizure free for 6 months postoperatively.

Central Nervous System Cysts↗
PubMed2005

Surgical strategies for approaching hypothalamic hamartomas causing gelastic seizures in the pediatric population: transventricular compared with skull base approaches.

OBJECT: The authors provide evidence that direct resection of hypothalamic hamartomas (HHs) can improve associated gelastic and nongelastic seizures. METHODS: Ten children younger than 17 years of age underwent resection of HHs (nine sessile and one pedunculated) that were causing refractory epilepsy. Lesions were approached from above transventricularly through a transcallosal anterior interforniceal approach in six cases, endoscopically through the foramen of Monro in one, and from below with a frontotemporal craniotomy including an orbitozygomatic osteotomy in three. Medical charts were reviewed retrospectively, and follow-up data were obtained through office records and phone calls. Follow-up periods ranged between 12 and 84 months (mean 16.8 months). All patients in whom the approach was from above had sessile HHs. Five were free from seizures at follow up and two had a reduction in seizures of at least 95%. The transventricular route allowed excellent exposure and visualization of the local structures during resection. Among the three patients in whom the approach was from below, one became free of seizure after two procedures and one had a 75% reduction in epilepsy; the latter two had sessile HHs. The exposure was inadequate, and critical tissue borders were not readily apparent. Although the HH was adequately exposed and resected, the epilepsy persisted in the third patient, who had a pedunculated lesion. The overall rate of major permanent hypothalamic complications appeared to be slightly lower for the orbitozygomatic osteotomy group. CONCLUSIONS: Sessile lesions are best approached from above. Approaches from below adequately expose pedunculated hamartomas. The likelihood of curing seizures seems to be higher when lesions are approached from above rather than from below.

Cerebral Ventricles↗
PubMed2004

Electrical stimulation of the anterior nucleus of the thalamus for the treatment of intractable epilepsy.

PURPOSE: Animal studies and sporadic case reports in human subjects have suggested that intermittent electrical stimulation of the anterior nucleus of the thalamus reduces seizure activity. We embarked on an open-label pilot study to determine initial safety and tolerability of bilateral stimulation of the anterior nucleus of the thalamus (ANT), to determine a range of appropriate stimulation parameters, and to begin to gather pilot efficacy data. METHODS: We report an open-label pilot study of intermittent electrical stimulation of the anterior nucleus of the thalamus in five patients (three men, two women; age range, 24-47 years), with follow-up between 6 and 36 months. All patients had intractable partial epilepsy. Four of the five patients also had secondarily generalized seizures. Stimulation was delivered by bilateral implantable, programmable devices by using an intermittent, relatively high-frequency protocol. Stimulation parameters were 100 cycles per second with charge-balanced alternating current; pulse width, 90 ms; and voltages ranging between 1.0 and 10.0 V. Seizure counts were monitored and compared with preimplantation baseline. RESULTS: Four of the five patients showed clinically and statistically significant improvement with respect to the severity of their seizures, specifically with respect to the frequency of secondarily generalized tonic-clonic seizures and complex partial seizures associated with falls. One patient showed a statistically significant reduction in total seizure frequency. No adverse events could clearly be attributed to stimulation. None of the patients could determine whether the stimulator was on or off at these parameters. CONCLUSIONS: Electrical stimulation of the ANT appears to be well tolerated. Preliminary evidence suggests clinical improvement in seizure control in this small group of intractable patients. Further controlled study of deep brain stimulation of the anterior nucleus is warranted.

Adult↗
PubMed2004

Treatment of refractory status epilepticus with hemispherectomy.

A 7-year-old boy with left hemiparesis secondary to right hemispheric cortical dysplasia was admitted to the hospital with increasing numbers of seizures. Magnetic resonance imaging showed a small dysplastic right hemisphere with abnormally thickened gyri and an apparently normal left hemisphere. Previous video-electroencephalogram (EEG) monitoring showed bilateral independent spikes and generalized slow spike-and-wave episodes on EEG and [18F]fluorodeoxyglucose (FDG) positron emission tomography scan demonstrated scattered areas of regional hypometabolism bilaterally; therefore hemispherectomy was not undertaken at that time. During this hospital stay, nonconvulsive status epilepticus developed and was refractory to multiple medical therapies including pentobarbital (PTB) coma. Burst-suppression pattern during PTB coma appeared to be generalized spike and wave, but when EEG was reviewed with increased time resolution spikes suggested a right hemisphere origin. The patient underwent bilateral intracarotid amobarbital spike-suppression test that showed only minimal suppression of epileptiform discharges with injection of the left carotid, but complete suppression of spike activity after right-sided carotid injection. A right hemispherectomy was performed with complete cessation of status epilepticus. Postoperative EEG showed no epileptiform discharges. Patient follow-up was limited to 12 months after surgery. The patient had regained the ability to walk unaided and was seizure free with a single antiepileptic medication. This case illustrates a potentially life-saving procedure for refractory status epilepticus and several techniques including a spike-suppression test to aid in prediction of cessation of seizures after hemispherectomy.

Amobarbital↗
PubMed2004

Respiratory syncytial virus infection and neurologic abnormalities: retrospective cohort study.

Respiratory syncytial virus is a common cause of acute respiratory infection in children. Previous reports have associated respiratory syncytial virus infection and acute neurologic symptoms, including apnea and seizures. This study examined the prevalence of acute neurologic symptoms associated with respiratory syncytial virus and non-respiratory syncytial virus respiratory infections in children requiring admission to a pediatric intensive care unit. We screened all admissions over a 4-year period at a single center, identifying children between birth and 2 years of age with bronchiolitis or acute upper respiratory infection. Children with a history of prematurity, preexisting medical conditions, or prior neurologic problems were excluded. Retrospective chart review of 236 admissions was conducted, identifying the etiology of respiratory infection and the presence or absence of acute neurologic signs or symptoms. This study demonstrated a prevalence of acute neurologic signs or symptoms in 36.4% of respiratory syncytial virus-negative patients (n = 115) and 39.1% in the respiratory syncytial virus-positive group (n = 121). Apnea, the most common symptom, was observed in 19.8% of respiratory syncytial virus-positive cases and 16.5% of negative patients. Seizures were reported in 6.6% of the positive cases and in 12.2% of the negative cohort. These differences showed no statistical significance. Although neurologic signs and symptoms are common in this population of children with acute respiratory infection, there was no significant difference in the prevalence of neurologic problems between respiratory syncytial virus-positive and -negative patients.

Academic Medical Centers↗
PubMed2002

Hypomagnesemic seizures: case report and presumed pathophysiology.

Hypomagnesemia has previously been recognized as an uncommon cause of seizures. The electrolyte abnormality is caused by poor gastrointestinal absorption or excessive renal wasting, both from a variety of causes. We report on a 5-week-old patient who developed hypomagnesemic seizures as a consequence of renal magnesium wasting. Although the exact pathophysiology of hypomagnesemic seizures remains uncertain, currently available information suggests that it is related to disinhibition of the N-methyl-D-aspartate-type glutamate receptor-sodium channel complex.

Epilepsy, Generalized↗
PubMed2002

Pena-Shokier phenotype: case presentation and review.

Pena-Shokier phenotype is an early lethal disorder involving multiple joint contractures, facial anomalies, and pulmonary hypoplasia. Alternative terms for this syndrome used in the literature include fetal hypokinesia syndrome, lethal congenital contracture syndrome, and Pena-Shokier syndrome type I. The etiology for the early cases was attributed to neuromuscular disease, with deformations owing to weakness or paralysis of the motor unit. An abnormality of spinal cord motoneurons has been postulated in some cases. Pena-Shokier phenotype can also result from blockade of the neuromuscular junction, as shown by recent observations with women expressing antibodies against the fetal acetylcholine receptor. It has been shown that the Pena-Shokier phenotype may result from intrauterine cerebral dysfunction as well, including acquired brain insults and congenital brain malformations. The ultimate prognosis for children with this disorder is dependent on the underlying etiology and the severity of pulmonary disease. The authors report a fatal case of Pena-Shokier phenotype with congenital polymicrogyria. To our knowledge, the case presented is the first reported Pena-Shokier phenotype associated with this type of brain malformation.

Abnormalities, Multiple↗