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Biomedical subjects

Harold L Rekate

Publications and source records attributed to Harold L Rekate.

At least 19 recordsLinked to original sources
PubMed2006

Segmental spinal dysgenesis: report of four cases and proposed management strategy.

INTRODUCTION: Segmental spinal dysgenesis, a rare developmental malformation, usually manifests during pregnancy or at birth. The resulting gross spinal instability necessitates spinal stabilization, which is inherently challenging in neonates. METHODS: We report four cases of segmental dysgenesis: three in the thoracolumbar region and one at the cervicothoracic junction. The latter was maintained in a custom orthosis that restricted all craniospinal motion while allowing routine care. Two neonates underwent surgical stabilization. The fourth patient will remain in a brace until 12-14 months old when fusion is planned. RESULTS: Fusion with rib autografts failed in the two neonates. One patient has been followed for 13 years and is paraplegic. The second patient was lost to follow up. The patient with the cervicothoracic dysgenesis maintained normal neurologic function until his death at 8 months of cardiac failure. The fourth patient is 12 months old and has been maintained in a thoracolumbar orthosis with stable neurologic function. CONCLUSION: Several factors contribute to the challenge of creating a stable fusion in neonates. Incomplete ossification of the vertebral bodies and poor results with allograft materials restrict fusion options. Neurologic deficits often prevent ambulation and decrease the axial-loading forces that enhance fusion. To allow children to grow and develop, we advocate rigid spinal immobilization for 12-18 months before spinal fusion (preferably, rib or fibular autograft). Given the already narrow spinal canal, the use of instrumentation is controversial. We advocate the use of instrumentation in infants only when a sound construct cannot be obtained with the graft alone.

Abnormalities, Multiple↗
PubMed2006

Invasive intracerebral schwannoma mimicking meningioma in a child.

CASE REPORT: An 8-year-old boy presented to the emergency department after a generalized tonic-clonic seizure that lasted for 5 min. Magnetic resonance imaging showed a 2x2 cm, intraaxial, contrast-enhanced cortical lesion in the posterior right frontal lobe. On several images the lesion appeared to be dural-based and was presumed to be a meningioma. The patient was placed on dilantin and returned 1 month later for elective surgical resection. OUTCOME: At surgery, a rim of intact pia was identified between the dura and the tumor. Although initial frozen-section analysis was consistent with meningioma, subsequent immunohistochemical staining and review at an outside institution established the diagnosis of intracerebral schwannoma. The patient's postoperative course was uncomplicated and he remains seizure-free with no sign of recurrence at 18 months. CONCLUSION: Intracerebral schwannomas are uncommon cortical lesions in children. Imaging characteristics alone can be misleading; neuropathological support is essential for accurate diagnosis.

Brain Neoplasms↗
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

Congenital cervical instability in a patient with camptomelic dysplasia.

INTRODUCTION: Camptomelic dysplasia (CD) is a rare autosomal dominant skeletal dysplasia classically characterized by bent bones of the extremities, tracheobronchial narrowing, thoracic kyphoscoliosis, and various degrees of phenotypic sex reversal. Most patients die of complications in infancy, although long-term survivors have been reported. CASE REPORT: We report a case of CD complicated by incomplete ossification of the cervical vertebral pedicles, resulting in congenital cervical instability and kyphosis. Closed reduction was performed, and the patient was fitted with a customized cervical orthosis. FINDING: He subsequently developed a complete spinal cord injury at the kyphotic level. This underscores the grim prognosis associated with neonatal cervical spinal instability.

Adult↗
PubMed2006

Pediatric subaxial cervical spine injuries: origins, management, and outcome in 51 patients.

OBJECT: In this study the authors evaluated the mechanisms and patterns of injury and the factors affecting management and outcome of pediatric subaxial cervical spine injuries (C3-7). METHODS: Fifty-one pediatric patients (38 boys and 13 girls; mean age 12.4 years, range 10 months-16 years) with subaxial cervical spine injuries were reviewed retrospectively. Motor vehicle accidents (MVAs) were the most common cause of injury. Overall, 12% presented with a dislocation, 63% with a fracture, 19% with a fracture-dislocation, and 6% with a ligamentous injury. The most frequently injured level was C6-7 (33%); C3-4 (6%) was least frequently involved. Sixty-four percent of patients were neurologically intact, 16% had incomplete spinal cord injuries (SCIs), 14% had complete SCIs, and three patients (6%) died after admission and before assessment. Treatment was conservative in 64%: seven (13%) wore a halo vest and 26 (51%) wore a rigid cervical orthosis. Surgery was performed in the other 18 patients (36%), with the breakdown as follows: 15 (30%) underwent an anterior approach, two (4%) had posterior approaches, and one (2%) had a combined approach. Postoperatively, four patients (8% who had a neurological deficit improved. The overall mortality rate was 8%; all deaths were related to MVAs. There were no surgery-related deaths or complications. CONCLUSIONS: Subaxial cervical spine injuries are common in children 9 to 16 years of age, and occur principally between C-5 and C-7. Multilevel injury is more common in children 8 years of age and older than in younger children and infants. Most patients with subaxial cervical spine injuries can be treated conservatively. Both anterior and posterior approaches are safe and effective.

Adolescent↗
PubMed2006

Skeletal dysplasia involving the subaxial cervical spine. Report of two cases and review of the literature.

Because skeletal dysplasias are primary disorders of bone, they have not been commonly understood as neurosurgical diseases. Nevertheless, neurosurgical complications are commonly encountered in many cases of dysplasia syndromes. The authors present two cases of skeletal dysplasia that caused overt instability of the cervical spine. One patient with a diagnosis of Gorham disease of the cervical spine was treated with prolonged fixation in a halo brace after an initial attempt at instrumentation with a posterior occiput--C4 fusion. The other patient, who at birth was identified to have camptomelic dysplasia, has been treated conservatively from the outset. Although these two patients presented with different disorders--in one patient adequate mature bone never formed and in the other patient progressive bone loss became apparent after a seemingly normal initial development--these cases demonstrate unequivocally that surgical options for fusion are ultimately limited by the quality of the underlying bone. In patients in whom the bone itself is inadequate for use as a substrate for fusion, there are currently limited treatment options. Future improvements in our understanding of chondrogenesis and ossification may lead to the design of superior methods of encouraging fusion in these patients; however, at the present time, long-term maintenance in a halo brace may, in fact, be the only treatment.

Bone Diseases, Developmental↗
PubMed2006

Isolated Langerhans cell histiocytosis of the infundibulum presenting with fulminant diabetes insipidus.

INTRODUCTION: Langerhans cell histiocytosis (histiocytosis X) is a rare disorder that can manifest with solitary bony lesions or disseminated disease in various tissues. A common manifestation of the disease is diabetes insipidus even in the absence of neural involvement. Disseminated disease often involves the central nervous system, but only six isolated lesions in the infundibulum have been reported. CASE REPORT: An 18-year-old male had failed to develop secondary sexual characteristics. He also had diabetes insipidus for more than 1 year. Magnetic resonance imaging (MRI) of the brain showed a 1-cm homogeneously enhancing mass in the region of the infundibulum. No other lesions were found in other organ systems. The patient underwent an orbitozygomatic osteotomy and pterional craniotomy. The lesion, which was adherent to the infundibulum, was partially resected. Microscopic analysis showed multiple lymphocytes and eosinophils with Langerhans cells that stained positive for S-100. Langerhans cell histiocytosis was diagnosed, and the patient was discharged on postoperative day 6 with no neurological deficits. His diabetes insipidus persisted, and he underwent intensity-modulated radiation therapy to the sellar region. CONCLUSIONS: Isolated Langerhans cell histiocytosis of the infundibulum is rare. The usual presentation is hypothalamic-pituitary axis dysfunction and diabetes insipidus. Patients with diabetes insipidus of unknown origin should undergo MRI of the sellar region to rule out infundibular abnormalities.

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

Endoscopic resection of hypothalamic hamartoma using a novel variable aspiration tissue resector.

OBJECTIVE: We present a novel variable aspiration tissue resector for use with neuroendoscopy. METHODS: Two patients, 4 and 14 years old, respectively, presented with intractable gelastic seizures refractory to maximal medical therapies. Magnetic resonance imaging showed mass lesions of the third ventricle consistent with hypothalamic hamartoma. RESULTS: The patients underwent magnetic resonance imaging wand-guided endoscopic resection of the tumor with the Suros novel variable aspiration tissue resector. There were no device-associated complications or adverse events. The hamartoma was disconnected in one patient, and gross total resection was achieved in the other. CONCLUSION: Endoscopy for tumor resection is still frustrated by the lack of surgical tools, such as ultrasonic aspirators, comparable with those available for use during open procedures. The variable-aspiration tissue resector reported here can be used to resect tumor tissue safely. These two cases demonstrate that gross total resection of small hypothalamic hamartomas is feasible with minimal morbidity through an endoscopic approach.

Adolescent↗
PubMed2006

Severe intracranial hypertension in slit ventricle syndrome managed using a cisterna magna-ventricle-peritoneum shunt.

OBJECT: Severely increased intracranial pressure (ICP) can be life threatening in patients who had previously undergone shunt treatment but who do not experience ventricular enlargement. The authors analyzed the utility of placing shunts into the cisterna magna concurrently with ventricular shunts in patients who were not candidates for lumboperitoneal (LP) shunt placement. METHODS: Ten patients treated with cisterna magna-ventricle-peritoneum (CMVP) shunts for complex problems of shunt function were reviewed retrospectively. All patients had documented increases in ICP and ventricles that did not expand despite life-threatening increases (> 80 mm Hg in one case) in ICP. Between 1995 and 2003, 10 patients (four males and six females, age range 4-32 years) were identified as having life-threatening increases in ICP despite small or slit-like ventricles on imaging studies. Each episode was documented with intraparenchymal pressure monitoring. All patients had documented ventricular catheter failures at the time of the intervention, and all had undergone at least one previous attempt to treat the condition with a valve upgrade and replacement of the ventricular catheter. Three patients had achondroplasia, four had spina bifida, and three had a preexisting Chiari malformation Type I. All patients improved after the procedure, and none suffered permanent complications. For at least 48 hours after surgery, all patients underwent intraparenchymal monitoring of ICP (an intraparenchymal monitor was used that documented normal ICP). CONCLUSIONS: The CMVP shunts are an excellent option for patients who are not candidates for LP shunts but who have high ICP and ventricles that do not enlarge at shunt failure. The ability to access the spinal fluid in the cortical subarachnoid space presumably accounts for this success.

Adolescent↗
PubMed2006

Surgical management of arteriovenous malformations in children.

OBJECT: Children compose 3 to 20% of the patients with arteriovenous malformations (AVMs); however, AVMs are responsible for 30 to 50% of intracranial hemorrhages in children. METHODS: The medical records of 82 children with 84 AVMs treated surgically between 1983 and 2005 were reviewed. Fifty-two patients (63%) presented with hemorrhage, 13.4% presented with seizures, and AVMs in 12% were found incidentally. Patients with brainstem lesions presented at a significantly younger age (p = 0.002) than those harboring lesions in other locations. Frontal lobe lesions were significantly smaller than those in other locations, and thalamic lesions were significantly larger (p = 0.012 and 0.005, respectively). Most patients with Spetzler-Martin Grades I to III lesions underwent craniotomy only. Half of the patients with Grade IV and V lesions underwent embolization, craniotomy, and radiosurgery. The mean follow-up period was 43 months. Postoperatively, the initial obliteration rate was 65%, with a long-term obliteration rate of 90%. The perioperative mortality rate was 3.7%. Altogether, 81% of patients had excellent outcomes, and patients with Grade I lesions had the best outcomes. Of the 52 patients who presented with hemorrhage, 17% had fair or poor outcomes. The recurrence rate was 5.6%. CONCLUSIONS: Children with AVMs may be more prone than adults to present with a hemorrhage and to experience recurrence of the lesion after treatment. The authors favor resection for most AVMs in children and use embolization as a preoperative strategy for Grades II to V lesions treated surgically. Prehemorrhagic Grade IV and V lesions may best be treated conservatively and observed carefully for the development of symptoms. Long-term follow up of all patients is essential.

Cerebral Hemorrhage↗
PubMed2006

Synchronous endoscopy and microsurgery: a novel strategy to approach complex ventricular lesions. Report of three cases.

Simultaneous endoscopic and microsurgical (synchronous) approaches represent a new paradigm in the treatment of complex ventricular lesions. This technique is well suited for lesions that involve multiple ventricular or cisternal compartments, have a nonlinear axis, or adhere to critical anatomical or neurovascular structures. Two distinct operative corridors, one endoscopic and the other microsurgical, are used during synchronous approaches to address such lesions, increasing the likelihood of a safe and complete resection. The authors present the cases of two children and an adult treated via synchronous approaches. All patients had multi-compartmental lesions involving the ventricles and/or cisterns. One patient presented with a suprasellar Rathke cyst with a significant third ventricular component, one with a hypothalamic hamartoma having a substantial cisternal component, and the remaining patient with a choroid plexus papilloma in the left lateral ventricle that extended from midbody to the temporal horn. In the cases of the Rathke cyst and the hamartoma, debulking in the third ventricle and controlled detachment of the lesion from the hypothalamus were undertaken using endoscopy, and simultaneous resection of the suprasellar component was performed through a subfrontal craniotomy. In the case of the choroid plexus papilloma, selective cautery of the choroidal feeding vessels and detachment from the temporal tela choroidea were performed using endoscopy, and the tumor from the ventricular body to the atrium was resected via a craniotomy. In each case the resection concluded with the intersection of endoscopic and microsurgical fields. All three patients had good outcomes. Endoscopic and microsurgical approaches can be used concurrently to treat multicompartment ventricular and/or cisternal lesions with good results. The probable advantages of this method are more complete resection and improved safety.

Adolescent↗
PubMed2005

Treatment of refractory intracranial hypertension in a spina bifida patient by a concurrent ventricular and cisterna magna-to-peritoneal shunt.

CASE REPORT: A 20-year-old female born with a thoracic level myelomeningocele, Chiari II malformation, and hydrocephalus treated at birth developed clinical features of increased intracranial pressure (ICP) due to shunt malfunction. The patient became comatose. Her ICP remained high despite a functioning shunt and even after the ventricular catheter was exteriorized. Diagnostic imaging consistently demonstrated slit-like ventricles, a Chiari II malformation, and a tethered spinal cord. We attributed her neurological condition either to brainstem compression or increased ICP related to venous outlet obstruction at the foramen magnum. OUTCOME: The patient improved rapidly after undergoing a Chiari II decompression and placement of a shunt from the cisterna magna and upper cervical subarachnoid space to the peritoneum connected by a "Y" connector to the ventricular catheter. CONCLUSION: The complex hydrocephalus was effectively treated by this concurrent ventricular and cisterna magna-to-peritoneum shunt.

Adult↗
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

Emergency transcallosal resection of hypothalamic hamartoma for "status gelasticus".

Hypothalamic hamartomas are rare developmental malformations of the inferior hypothalamus. Typically they result in symptomatic, refractory mixed seizure disorder with trademark gelastic or laughing seizures. We present a 30-month-old boy with a hypothalamic hamartoma and a nearly 2-month history of near-continuous gelastic seizures, which we have labeled "status gelasticus." The seizures were refractory to multiple antiepileptic drugs (AEDs), and emergency transcallosal resection of the hypothalamic hamartoma was performed with resultant near-immediate cessation of the seizures. At 12-month follow-up, the patient was averaging one brief gelastic seizure every 2 weeks, with a longest seizure-free period of 2 months.

Child, Preschool↗