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J P Farmer

Publications and source records attributed to J P Farmer.

At least 19 recordsLinked to original sources
PubMed2002

Resection of the lesion in patients with hypothalamic hamartomas and catastrophic epilepsy.

BACKGROUND: Patients with hypothalamic hamartomas (HH) often have severe refractory epilepsy, incapacitating behavioral abnormalities, and cognitive decline. Attempts to control the seizure disorder by resection of apparently epileptogenic mesial temporal or other cortical structures have failed consistently. OBJECTIVE: To report a series of 13 patients in whom the hamartoma itself was resected. METHODS: All patients underwent preoperative evaluation between ages 2 and 33 years and had subtotal or complete resection of the hamartoma. Follow-up ranged from 1 to 5.5 years (mean: 2.8 y). RESULTS: Preoperatively, all patients had variable combinations of gelastic, complex partial, and generalized seizures. Eight had drop attacks. In addition, all had marked behavior abnormalities and cognitive impairment. Postoperatively, two patients are completely seizure-free and 11 are either seizure-free or have achieved a greater than 90% reduction of drop attacks and generalized tonic-clonic seizures. However, minor gelastic, complex partial, and atypical absence seizures have persisted in 11 patients, although at significantly reduced rates. In addition, there has been a dramatic improvement in behavior and cognition. Three patients had an anterior thalamic and one a capsular infarct, which left only minimal long-term deficits. Exact location of the lesion in relation to the interpeduncular fossa and the walls of the third ventricle correlated with extent of excision, seizure control, and complication rate. CONCLUSION: Resection can alleviate both the seizures and the behavioral and cognitive abnormalities of hypothalamic hamartomas, but complications are frequent.

Adolescent↗
PubMed2001

Brainstem Gliomas. A 10-year institutional review.

Case records of 37 patients with a diagnosis of brainstem glioma treated at the Montreal Children's Hospital from June 1989 to June 1999 were reviewed. 15 patients had diffuse pontine gliomas and 22 patients had focal forms of brainstem gliomas. The two groups were compared with respect to age, clinical evolution, radiological appearance, type of surgery practised, histological diagnosis, adjuvant treatments and survival. A non-pontine brainstem location, a cystic or exophytic component, bright enhancement with gadolinium injection, a histological diagnosis of pilocytic astrocytoma or ganglioglioma were favourable prognostic factors. Progression-free survival and overall survival were significantly worse in the group of patients with diffuse pontine gliomas. The relative impact of radical surgery and/or radiotherapy is analysed. Surgery coupled to adjuncts such as navigation, ultrasound and monitoring plays an important role for focal brainstem lesions. Focal/conformal radiotherapy has an adjuvant role but better treatments are needed for the diffuse pontine brainstem lesions.

Adolescent↗
PubMed2001

Intractable epilepsy after a functional hemispherectomy: important lessons from an unusual case. Case report.

Residual seizures after functional hemispherectomy occur in approximately 20% of patients with catastrophic epilepsy. These episodes are traditionally attributed to incomplete disconnection, persistent epileptogenic activity in the ipsilateral insular cortex, or bilateral independent epileptogenic activity. The authors report on the case of an 8-year-old boy with an intractable seizure disorder who had classic frontal adversive seizures related to extensive unilateral left hemispheric cortical dysplasia. The initial intervention consisted of extensive removal of the epileptic frontal and precentral dysplastic tissue and multiple subpial transections of the dysplastic motor strip, guided by intraoperative electrocorticography, Subsequently, functional hemispherectomy including insular cortex resection was performed for persistent attacks. After a seizure-free period of 6 months, a new pattern ensued, consisting of an aura of fear, dystonic posturing of the right arm, and unusual postictal hyperphagia coupled with an interictal diencephalic-like syndrome. Electroencephalography and ictal/interictal single-photon emission computerized tomography were used to localize the residual epileptic discharges to deep ipsilateral structures. Results of magnetic resonance imaging indicated a complete disconnection except for a strip of residual frontobasal tissue. Therefore, a volumetric resection of the epileptogenic frontal basal tissue up to the anterior commissure was completed. The child has remained free of seizures during 21 months of follow-up review. Standard hemispherectomy methods provide extensive disconnection, despite the presence of residual frontal basal cortex. However, rarely, and especially if it is dysplastic, this tissue can represent a focus for refractory seizures. This is an important consideration in determining the source of ongoing seizures posthemispherectomy in patients with extensive cortical dysplasia. It remains important to assess them fully before considering their disease refractory to surgical treatment.

Cerebral Cortex↗
PubMed2001

Reliability of intraoperative electrophysiological monitoring in selective posterior rhizotomy.

OBJECT: Selective posterior rhizotomy is a well-established treatment for spasticity associated with cerebral palsy. At most medical centers, responses of dorsal rootlets to electrical stimulation are used to determine ablation sites; however, there has been some controversy regarding the reliability of intraoperative stimulation. The authors analyzed data obtained from the McGill Rhizotomy Database to determine whether motor responses to dorsal root stimulation were reproducible. METHODS: A series of 77 patients underwent selective dorsal rhizotomy at a single medical center. The dorsal roots from L-2 to S-2 were stimulated to determine the threshold amplitude. The roots were then stimulated at 2 to 4 times the highest threshold with a 1-second 50-Hz train. A second stimulation run of the entire dorsal root was performed before it was divided into rootlets. Rootlets were individually stimulated and sectioned according to the extent of abnormal electrophysiological propagation. Motor responses were recorded by electromyography and were also assessed by a physiotherapist, and grades of 0 to 4+ were assigned. The difference in grades between the first and second stimulation trains was determined for 752 roots. Statistical analysis demonstrated a clear consistency in motor responses between the two stimulation runs, both in the electromyographic readings and the physiotherapist's assessment. More than 93% of dorsal roots had either no change or a difference of only one grade between the two trials. Furthermore, the vast majority of dorsal roots assigned a grade of 4+ at the first trial maintained the same maximally abnormal electrophysiological response during the second stimulation run. CONCLUSIONS: This study indicates that currently used techniques are reproducible and reliable for selection of abnormal rootlets. Intraoperative electrophysiological stimulation can be valuable in achieving a balance between elimination of spasticity and preservation of underlying strength.

Cerebral Palsy↗
PubMed2000

Dysgenetic mesial temporal sclerosis: an unrecognized entity.

Mesial temporal sclerosis (MTS) is the most frequently encountered lesion in adult patients with intractable temporal epilepsy; it is found in isolation in approximately two-thirds of surgically treated cases. Whereas the exact etiology of MTS is still controversial, several reports suggest that this pathologic lesion is both the cause and the consequence of chronic seizures and develops progressively during childhood secondary to recurrent seizures. In order to evaluate the clinical importance of MTS in children, we retrospectively reviewed the clinical charts of children who underwent surgery for medically intractable temporal epilepsy and report cases presenting an amygdalo-hippocampic dual pathology. Six children aged 1.5-16 years (mean +/- SD: 7.5 +/- 3 years) presenting with partial complex seizures (5 cases) or extension spasms (1 case), with onset from 6 months to the age of 8.5 years (mean seizure onset +/- SD: 3 +/- 5 years) underwent anterior temporal lobectomy including resection of the amygdala and hippocampus. All patients exhibited variable degrees of severity of neuronal loss and gliosis in the amygdala and/or hippocampus. The pathological picture of MTS was not isolated, however. Careful pathological examination has thus shown foci of amygdalo-hippocampic neuronal dysplasia in six patients, with concomitant bilaminated fascia dentata in two cases. Postoperatively, no mortality or morbidity was encountered. After a mean follow-up of 2.5 years, four patients are seizure free. One patient had a 80% rate of improvement in seizure frequency, though still having occasional febrile convulsions. In another patient, complex partial seizures resolved, but rare episodes of absence were still observed. These data are in keeping with the hypothesis that MTS could be secondary to repeated seizures. The analysis of this series of patients could suggest that mesiotemporal dysplastic lesions within the amygdalo-hippocampic structures induce seizures, which, in turn, will favor the development of MTS during childhood. MTS could then lead to synaptic reorganization, which can express abnormal hyperexcitability and result in more recurrent seizures. In this way a vicious circle is set up, which may explain the progression of seizures in some patients.

Adolescent↗
PubMed2000

Primitive neuroectodermal tumors of the brainstem: investigation of seven cases.

OBJECTIVE: We discuss the clinical aspects, pathology, and molecular genetics of 7 patients with primitive neuroectodermal tumors (PNETs) arising in the brainstem that were treated at our institution from 1986 through 1995. Most neuro-oncologists avoid performing biopsies in children with pontine tumors. This article raises the question as to whether biopsies should be performed, because treatment recommendations might differ if a PNET was diagnosed rather than a pontine glioma. PATIENTS AND METHODS: We reviewed the clinical neuro-oncology database and the files of the Division of Neuropathology at New York University Medical Center from 1986 through 1995 and identified 7 histologically confirmed PNETs arising in the brainstem among 146 pediatric brainstem tumors. The clinical, neuroradiological, and neuropathological data were reviewed. Postmortem examinations were performed in 2 cases. Formalin-fixed, paraffin-embedded tumor tissues were also available in 6 of 7 patients that were tested for p53 gene mutations using single-strand conformation polymorphism analysis. We also tested 9 cerebellar PNETs, 9 brainstem gliomas, and 3 normal brains for p53 gene mutations as controls. RESULTS: All 7 patients presented with focal cranial nerve deficits, and 2 were also hemiparetic. The median age at diagnosis was 2.7 (1-8 years). Magnetic resonance imaging (MRI) characteristics included a focal intrinsic exophytic nonenhancing brainstem lesion that had low T1-weighted and high T2-weighted signals. Hydrocephalus was present in 5 patients at diagnosis, 3 of whom had leptomeningeal dissemination. Meningeal dissemination occurred later in the course of the disease in 3 other patients. Five children required shunts at diagnosis and another 2 at recurrence. Despite therapy, all 7 PNET patients died within 17 months of diagnosis with a mean survival of 8 (4-17) months. No mutation in the p53 gene was detected. CONCLUSIONS: Brainstem PNETs tend to arise at a younger age than brainstem gliomas and medulloblastomas. The MRI pattern suggests a localized rather than a diffuse intrinsic nonenhancing brainstem tumor. Like other PNETs, brainstem PNETs have a high predilection to disseminate within the central nervous system. The absence of p53 mutations is similar to other PNETs. Despite their origin close to the cerebellum, brainstem PNETs exhibit a more aggressive behavior and result in worse clinical outcomes than do cerebellar PNETs.

Brain Neoplasms↗
PubMed1998

Low-grade astrocytomas in children: evolving management strategies.

Developments in imaging and in neurosurgical techniques over the past decade have substantially altered the management of children with low-grade astrocytoma. Indications for surgery have become more clearly defined, and a larger proportion of children undergo complete or subtotal resection than in the past. Fewer receive adjuvant therapy, even though the options in this regard are more numerous now and theoretically likely to result in less morbidity than conventional external beam radiotherapy. This review will address in particular the correlations between location, imaging appearance, and behavior that need to be more widely appreciated, and present recommendations regarding the management of these tumors.

Astrocytoma↗
PubMed1998

Pediatric brain stem gliomas: a review.

Tumors arising in the brain stem, comprising the midbrain, pons, and medulla oblongata, are now recognized as distinct clinico-pathological entities. Advances in neurosurgical techniques have made surgery not only feasible but the treatment of choice for some of these tumor types. Previously the mainstay of treatment, radiotherapy is now used more selectively. This article reviews the current state of knowledge with regard to tumors arising in the brain stem, the therapeutic options available for each, and provides recommendations with regard to management.

Brain Neoplasms↗
PubMed1998

Magnetic resonance imaging in children with voiding dysfunction: is it indicated?

PURPOSE: We evaluated the role of magnetic resonance imaging (MRI) of the lumbosacral spinal cord in children with complicated voiding dysfunction and normal neuro-orthopedic examination. MATERIALS AND METHODS: We reviewed the records of 32 consecutive children with complicated enuresis who were referred for neurosurgical evaluation, including those with a history of refractory voiding dysfunction or incontinence associated with persistent vesicoureteral reflux, encopresis, or associated leg or back pain. Nine patients were excluded from study because of urethral or anorectal anomalies, or failure to meet the inclusion criteria. Eligible for study inclusion were 23 children with a mean age of 8.9 years. Complete neurological and orthopedic examinations were normal in all patients except 1 with mild scoliosis and 1 with congenital facial palsy. RESULTS: Urodynamic studies revealed instability in 14 cases, hypertonia in 7, hyporeflexia in 2 and detrusor-sphincter dyssynergia in 4. Skeletal abnormalities, mostly spina bifida occulta, were detected in 16 of the 23 children (70%). Spinal MRI was normal in 21 patients (91.3%), including 1 with a tethered cord and lipoma associated with a complex skeletal abnormality, and 1 with a nonprogressive, nonsurgical T7 to T9 syrinx. Only the case of lipoma required neurosurgical intervention. CONCLUSIONS: The value of MRI is limited in children with voiding dysfunction and a normal neuro-orthopedic assessment. This study should be reserved for patients with associated neuroorthopedic findings or complex skeletal deformity on plain x-ray.

Adolescent↗
PubMed1998

Bladder function before and after selective dorsal rhizotomy in children with cerebral palsy.

PURPOSE: Approximately a third of children with cerebral palsy are expected to present with dysfunctional voiding symptoms. Selective dorsal rhizotomy, which is indicated for managing lower extremity spasticity in children with cerebral palsy, also has the potential of affecting bladder function. We evaluate the impact of selective dorsal rhizotomy on bladder function by comparing preoperative and postoperative symptoms, and urodynamic parameters in children undergoing selective dorsal rhizotomy for spasticity. MATERIALS AND METHODS: We reviewed urodynamic studies in 25 boys and 15 girls with a mean age plus or minus standard deviation of 5.43+/-2.1 years who underwent selective dorsal rhizotomy for spasticity at our institution between January 1992 and September 1995. Urodynamics were performed preoperatively only in 22 patients, preoperative and postoperatively in 13, and postoperatively only in 5. Preoperative urodynamic studies were done within 2 weeks of surgery and postoperative studies were done at least 6 months after surgery (mean 1.32+/-0.65 years). RESULTS: Of the 35 patients with preoperative urodynamic studies total bladder capacity, pressure specific volumes and full resting pressure were abnormal for age in 23 (65.7%). In addition, 17 of the 23 children (74%) were completely asymptomatic. In the group that underwent preoperative and postoperative urodynamic studies there was significant improvement in total bladder capacity (p <0.005) and pressure specific volumes (p <0.005) using the paired Student t test. All children had neurological improvement postoperatively, 5 of 7 (71%) who were incontinent preoperatively became continent and none had deterioration on urodynamics. CONCLUSIONS: At least half of the children with spastic cerebral palsy have clinically silent bladder dysfunction. Selective dorsal rhizotomy improves spasticity and significantly improves bladder storage characteristics. We propose that urodynamic studies be included in the evaluation of children with spastic cerebral palsy who are possible candidates for selective dorsal rhizotomy to treat lower limb spasticity.

Cerebral Palsy↗
PubMed1998

Continuous unilateral epileptiform discharge and language delay: effect of functional hemispherectomy on language acquisition.

PURPOSE: To assess the efficacy of functional hemispherectomy in promoting language acquisition in a child with severe language delay and continuous left hemispheric epileptiform discharge in the absence of clinical seizures. We report a 6-month-old girl who initially presented with a right hemiparesis secondary to a lesion of probable prenatal origin in the distribution of the left middle cerebral artery. Weeks later, she developed infantile spasms. At 1.5 years of age, because of intractable seizures, the patient had fenestration of the left porencephalic cyst and anterior temporal lobectomy. The seizures ceased; however, language development remained limited to 35 words at 3.5 years of age. The EEG showed almost continuous epileptiform activity over the left hemisphere with no independent epileptiform potentials contralaterally. She underwent a functional left hemispherectomy. METHODS: Imaging, electroencephalographic investigation, pre- and postoperative psychological and speech assessment were carried out. RESULTS: Considerable language, speech, and behavior improvement was noted within 2 months of surgery. CONCLUSIONS: Interictal epileptiform discharges can interfere with the development of contralateral hemispheric function in the absence of clinical seizures. Early functional hemispherectomy may have a role in promoting optimal language development in appropriately selected patients. Although the primary indication for functional hemispherectomy is to control intractable seizures, a secondary proposed indication is to reduce functional impairment of the other hemisphere by electrical interference.

Brain↗
PubMed1998

Tuberous sclerosis complex and neonatal seizures.

Tuberous sclerosis complex is a multisystemic neurocutaneous disorder, manifesting variably during infancy and childhood that remains poorly described in neonates. When described in this population, tuberous sclerosis complex is most commonly associated with cardiac rhabdomyomas and brain tumors, but is rarely mentioned as an etiology for neonatal seizures. We report two children with tuberous sclerosis presenting for neonatal seizures. Neuroimaging findings of neonatal tuberous sclerosis complex are discussed. Given the absence of many of the traditional stigmata of tuberous sclerosis complex in the neonate, seizures should be considered an important presenting feature of this disorder in this particular age group.

Brain↗
PubMed1996

Encephaloduroarterio-synangiosis in a child with sickle cell anemia and moyamoya disease.

We report a black girl with sickle cell anemia. On prophylactic exchange transfusion protocol, she experienced cerebrovascular accidents at 3 and 3.5 years of age, both associated with transient right hemiparesis. At 7.5 years of age, she presented with a partial motor seizure and a left hemiparesis. A cerebral angiogram demonstrated stenosis at the origins of both middle and anterior cerebral arteries bilaterally with extensive basal collateralization. She underwent uncomplicated bilateral encephaloduroarteriosynangiosis (EDAS) procedures using both superficial temporal arteries. At age 9 years, the patient presented with a severe headache and tunnel vision secondary to a stenosis of both posterior cerebral arteries. She underwent bilateral EDAS procedures using both occipital arteries. No complication was encountered. Postoperative cerebral angiogram demonstrated impressive neovascularity at the sites of all four EDAS procedures. Different treatment options of moyamoya disease are discussed.

Anemia, Sickle Cell↗
PubMed1996

Cauda equina histiocytosis X.

A young child was admitted with a cauda equina syndrome believed to be progressive, but unrelated to a congenital anomaly. Magnetic resonance imaging studies revealed the presence of an intradural tumor in the cauda equina. A yellow pasty tumor with nerve root infiltration was identified at surgery. Histologic features were pathognomonic for histiocytosis X. The patient's management and review of the literature are discussed.

Cauda Equina↗
PubMed1996

Traumatic aneurysm from shaken baby syndrome: case report.

OBJECTIVE AND IMPORTANCE: We present a 6-week-old infant who developed a traumatic aneurysm from clearly documented shaken baby syndrome. Despite the theoretical similarity in the mechanism of such injuries, this is the first aneurysm reported that resulted from such a cause. The infant is also the youngest reported patient to have suffered from a traumatic aneurysm. CLINICAL PRESENTATION: Police records documented shaking of the child as well as direct impact on the child's head. Three weeks later, the patient developed an intracerebral hemorrhage, which was revealed by angiography to have resulted from a pericallosal artery aneurysm. TECHNIQUE: The aneurysm was totally resected through a porencephalic cyst, which had developed secondary to ischemic injury to the brain. CONCLUSION: The temporal course, as well as the location of this traumatic aneurysm, is similar to that in older patients.

Cerebral Angiography↗
PubMed1996

Use of the prone position in the MRI evaluation of spinal cord retethering.

In order to determine the impact of magnetic resonance imaging (MRI) in the management of spinal cord retethering, we retrospectively reviewed case and imaging records of 51 patients who underwent MRI examination in supine and prone positions. Group 1 included 8 control patients without cord tethering. They exhibited a normal level of the conus medullaris with normal surrounding subarachnoid space, and consistent anterior migration of the conus within the dural sac on MRI in prone position. Group 2 included 17 patients with tethered cord secondary to occult spinal dysraphism (spinal cord lipoma in 6 patients, thick filum terminale in 4, diastematomyelia in 4, myelomeningocele manqué in 2, and dermoid tumour in 1). Supine and prone MRI performed at a median period of time of 6 months after untethering showed resolution of posterior tethering in 5 out of the 7 patients who exhibited pre-operatively dorsal attachment of the spinal cord to the dura. Anterior migration of the conus or of the cord/filum complex in prone position was observed in only 24% of the cases. Group 3 included 26 patients with secondary tethered cord following prior myelomeningocele closure. Their MRI performed at a median interval of time of 11 months following untethering demonstrated resolution of the posterior cord tethering in only 8 out of the 24 patients who exhibited this feature pre-operatively. Anterior migration within the expanded dural sac was never noted in this group. We conclude that spine MRI is of limited value and that prone-positioned MRI is of no additional use in the evaluation of spinal cord retethering.

Adolescent↗
PubMed1996

Comparison of syringopleural and syringosubarachnoid shunting in the treatment of syringomyelia in children.

Case records from the Montreal Children's Hospital containing the diagnosis of shunted syringomyelia were retrospectively reviewed. From 1984 to 1994, 31 patients had their syrinx treated by either syringopleural (19 cases, Group A) or syringosubarachnoid (13 cases, Group B) shunting. One patient was included in both groups. Associated diagnoses included: in Group A, two cases of Chiari I and 14 of Chiari II malformations, 14 cases of shunted hydrocephalus, 13 cases of spina bifida aperta, and three cases of spina bifida occulta; Group B, four cases of Chiari I and two of Chiari II malformations, four cases of shunted hydrocephalus, two cases of spina bifida aperta, and five cases of spina bifida occulta. Eight Group A and six Group B patients had undergone prior posterior fossa decompression. Motor deficits predominated in both groups and arachnoiditis was a uniform operative finding. Neurological follow-up examinations showed 11 Group A patients improved and eight stabilized, whereas on magnetic resonance imaging, 12 cavities appeared to have collapsed, five were markedly reduced, and one had increased. One patient underwent reoperation for pleural effusions and one for shunt displacement. In Group B, one patient improved, eight stabilized, three worsened neurologically, and one was lost to follow-up review. Radiologically, one cavity appeared to have collapsed, six were significantly reduced, two were unchanged, and three had enlarged. The authors conclude that syringopleural shunting is a valuable option for controlling syringomyelia in patients without Chiari malformation or in patients who have previously undergone a craniovertebral decompression or are otherwise asymptomatic from their Chiari malformation.

Adolescent↗