Iman Feiz-Erfan

Transcallosal Resection of Hypothalamic Hamartoma for Intractable Epilepsy

Summary:  Purpose: To present the results of transcallosal surgical resection of hypothalamic hamartoma (HH) in 26 patients with refractory epilepsy in a prospective outcome study.

TREATMENT OPTIONS FOR THIRD VENTRICULAR COLLOID CYSTS: COMPARISON OF OPEN MICROSURGICAL VERSUS ENDOSCOPIC RESECTION

OBJECTIVEWe retrospectively reviewed our experience treating third ventricular colloid cysts to compare the efficacy of endoscopic and transcallosal approaches. METHODSBetween September 1994 and March 2004, 55 patients underwent third ventricular colloid cyst resection. The transcallosal approach was used in 27 patients; the endoscopic approach was used in 28 patients. Age, sex, cyst diameter, and presence of hydrocephalus were similar between the two groups. RESULTSThe operating time and hospital stay were significantly longer in the transcallosal craniotomy group compared with the endoscopic group. Both approaches led to reoperations in three patients. The endoscopic group had two subsequent craniotomies for residual cysts and one repeat endoscopic procedure because of equipment malfunction. The transcallosal craniotomy group had two reoperations for fractured drainage catheters and one operation for epidural hematoma evacuation. The transcallosal craniotomy group had a higher rate of patients requiring a ventriculoperitoneal shunt (five versus two) and a higher infection rate (five versus none). Intermediate follow-up demonstrated more small residual cysts in the endoscopic group than in the transcallosal craniotomy group (seven versus one). Overall neurological outcomes, however, were similar in the two groups. CONCLUSIONCompared with transcallosal craniotomy, neuroendoscopy is a safe and effective approach for removal of colloid cysts in the third ventricle. The endoscope can be considered a first-line treatment for these lesions, with the understanding that a small number of these patients may need an open craniotomy to remove residual cysts.

Zoonotic Onchocerca lupi infection in a 22-month-old child in Arizona: first report in the United States and a review of the literature.

A 22-month-old girl presented with neck pain and stiffness and magnetic resonance imaging showed an extradural mass extending from C2 through the C4 level with moderate to severe compression of the cord. A left unilateral C2-C4 laminectomy was performed revealing an extradural rubbery tumor; a small biopsy was obtained. Examination of stained tissue revealed the presence of a parasitic worm that was identified as a gravid female Onchocerca lupi. A magnetic resonance imaging at 7 weeks follow-up showed a significantly decreased size of the enhancing lesion and the patients symptoms gradually resolved. This is the first report of zoonotic O. lupi in the United States. The parasite has been reported in dogs and cats in the western United States, and from people in four cases reported from Europe. A great deal more needs to be learned, including full host range and geographic distribution, before we fully understand O. lupi infections in animals and man.

Cavernous Malformation of the Trigeminal Nerve Manifesting with Trigeminal Neuralgia: Case Report

OBJECTIVE AND IMPORTANCE:We describe a patient with a cavernous malformation within the trigeminal nerve at the nerve root entry zone who presented with trigeminal neuralgia. CLINICAL PRESENTATION:A 52-year-old woman sought treatment after experiencing dizziness and lancinating left facial pain for almost a year. Neurological examination revealed diminished sensation in the distribution of the trigeminal nerve on the left. Magnetic resonance imaging demonstrated a minimally enhancing lesion affecting the trigeminal nerve. INTERVENTION:The patient underwent a retrosigmoid craniotomy. At the nerve root entry zone, the trigeminal nerve was edematous with hemosiderin staining. The lesion, which was resected with microsurgical technique, had the appearance of a cavernous malformation on gross and histological examination. The patients pain improved significantly after resection. CONCLUSION:Cavernous malformations can afflict the trigeminal nerve and cause trigeminal neuralgia. Microsurgical excision can be performed safely and is associated with improvement in symptoms.

Microsurgical management of spinal schwannomas: evaluation of 128 cases.

OBJECT The authors conducted a study to evaluate the clinical characteristics and surgical outcomes in patients with spinal schwannomas and without neurofibromatosis (NF). METHODS The data obtained in 128 patients who underwent resection of spinal schwannomas were analyzed. All cases with neurofibromas and those with a known diagnosis of NF Type 1 or 2 were excluded. Karnofsky Performance Scale (KPS) scores were used to compare patient outcomes when examining the anatomical location and spinal level of the tumor. The neurological outcome was further assessed using the Medical Research Council (MRC) muscle testing scale. RESULTS Altogether, 131 schwannomas were treated in 128 patients (76 males and 52 females; mean age 47.7 years). The peak prevalence is seen between the 3rd and 6th decades. Pain was the most common presenting symptom. Gross-total resection was achieved in 127 (97.0%) of the 131 lesions. The nerve root had to be sacrificed in 34 cases and resulted in minor sensory deficits in 16 patients (12.5%) and slight motor weakness (MRC Grade 3/5) in 3 (2.3%). The KPS scores and MRC grades were significantly higher at the time of last follow-up in all patient groups (p = 0.001 and p = 0.005, respectively). CONCLUSIONS Spinal schwannomas may occur at any level of the spinal axis and are most commonly intradural. The most frequent clinical presentation is pain. Most spinal schwannomas in non-NF cases can be resected totally without or with minor postoperative deficits. Preoperative autonomic dysfunction does not improve significantly after surgical management.

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.

Distal lenticulostriate artery aneurysm rupture presenting as intraparenchymal hemorrhage: case report.

OBJECTIVE AND IMPORTANCE:Aneurysms involving the distal lenticulostriate artery branches are a rare cause of spontaneous intracerebral hemorrhage. We report a case of ruptured lenticulostriate aneurysm in an otherwise healthy patient and review the literature on this topic. CLINICAL PRESENTATION:Computed tomography showed a right basal ganglia hemorrhage in a 44-year-old Native American woman with acute left hemiparesis. Cerebral angiography showed a 2-mm aneurysm in a distal lenticulostriate artery branch. TECHNIQUE:A pterional craniotomy was performed on a delayed basis using computed tomographic angiography and frameless stereotactic guidance. The basal ganglia hematoma was evacuated, and the aneurysm was identified and clipped using microsurgical technique. Because the base of the aneurysm involved a portion of the parent vessel wall, it was wrapped with cotton and reinforced with cyanoacrylate glue. The patient did well after surgery and was discharged to home with outpatient rehabilitation on the third postoperative day. CONCLUSION:Although intraparenchymal hemorrhages are fairly common, the underlying vascular abnormality is rarely identified. Most are related to hypertensive vascular degeneration, rupture of a Charcot-Bouchard aneurysm, or both. When intracerebral hemorrhage occurs in young patients, however, aggressive investigation is warranted to rule out a structural vascular abnormality.

Biomechanical comparison of occipitoatlantal screw fixation techniques: Laboratory investigation

OBJECT The stability provided by 3 occipitoatlantal fixation techniques (occiput [Oc]-C1 transarticular screws, occipital keel screws rigidly interconnected with C-1 lateral mass screws, and suboccipital/sublaminar wired contoured rod) were compared. METHODS Seven human cadaveric specimens received transarticular screws and 7 received occipital keel-C1 lateral mass screws. All specimens later underwent contoured rod fixation. All conditions were studied with and without placement of a structural graft wired between the skull base and C-1 lamina. Specimens were loaded quasistatically using pure moments to induce flexion, extension, lateral bending, and axial rotation while recording segmental motion optoelectronically. Flexibility was measured immediately postoperatively and after 10,000 cycles of fatigue. RESULTS Application of Oc-C1 transarticular screws, with a wired graft, reduced the mean range of motion (ROM) to 3% of normal. Occipital keel-C1 lateral mass screws (also with graft) offered less stability than transarticular screws during extension and lateral bending (p < 0.02), reducing ROM to 17% of normal. The wired contoured rod reduced motion to 31% of normal, providing significantly less stability than either screw fixation technique. Fatigue increased motion in constructs fitted with transarticular screws, keel screws/lateral mass screw constructs, and contoured wired rods, by means of 19, 5, and 26%, respectively. In all constructs, adding a structural graft significantly improved stability, but the extent depended on the loading direction. CONCLUSIONS Assuming the presence of mild C1-2 instability, Oc-C1 transarticular screws and occipital keel-C1 lateral mass screws are approximately equivalent in performance for occipitoatlantal stabilization in promoting fusion. A posteriorly wired contoured rod is less likely to provide a good fusion environment because of less stabilizing potential and a greater likelihood of loosening with fatigue.

Incidence and pattern of direct blunt neurovascular injury associated with trauma to the skull base.

OBJECT Skull base fractures are often associated with potentially devastating injuries to major neural arteries in the head and neck, but the incidence and pattern of this association are unknown. METHODS Between April and September 2002, 1738 Level 1 trauma patients were admitted to St. Josephs Hospital and Medical Center in Phoenix, Arizona. Among them, a skull base fracture was diagnosed in 78 patients following computed tomography (CT) scans. Seven patients had no neurovascular imaging performed and were excluded. Altogether, 71 patients who received a diagnosis of skull base fractures after CT and who also underwent a neurovascular imaging study were included (54 men and 17 women, mean age 29 years, range 1-83 years). Patients underwent CT angiography, magnetic resonance angiography, or digital subtraction angiography of the head and craniovertebral junction, or combinations thereof. RESULTS Nine neurovascular injuries were identified in six (8.5%) of the 71 patients. Fractures of the clivus were very likely to be associated with neurovascular injury (p < 0.001). A high risk of neurovascular injury showed a strong tendency to be associated with fractures of the sella turcica-sphenoid sinus complex (p = 0.07). CONCLUSIONS The risk of associated blunt neurovascular injury appears to be significant in Level 1 trauma patients in whom a diagnosis of skull base fracture has been made using CT. The incidence of neurovascular trauma is particularly high in patients with clival fractures. The authors recommend neurovascular imaging for Level 1 trauma patients with a high-risk fracture pattern of the central skull base to rule out cerebrovascular injuries.

Indications for surgical fusion of the cervical and lumbar motion segment.

Study Design. A literature review and the authors’ clinical experience for the indication of fusion in the degenerative lumbar and cervical spine is provided. Objective. To establish absolute and relative criteria for the indication for fusion in the degenerative cervical and lumbar spine. Summary of Background Data. Fusion in the cervical and lumbar degenerative spine is indicated under certain strict criteria. However, fusion in circumstances not meeting these criteria is controversial. Method. A review of the literature and the authors’ experience concerning indication and criteria of fusion in degenerative, lumbar, and cervical spine is provided. Results. Fusion for the unstable spine related to trauma, infection, and tumors is relatively accepted. However, indications for fusion for degenerative, cervical, and lumbar spine are more controversial. Conclusion. Lumbar and cervical fusion in the degenerative spine is frequently performed. Certain criteria have been established when a fusion should be considered. However, even these are not universally accepted. Strict prospective studies are needed to determine when a fusion of the degenerative, cervical, and lumbar spine is indicated. Patients with severe radicular pain may be considered for surgery after a comprehensive trial of conservative management. Fusion is usually necessary after a cervical discectomy, especially when spondylosis or osteophytic compression is present. Lumbar fusion is rarely indicated for routine discectomy. In patients with mechanical back or neck pain, surgery should only be considered after conservative measures have been exhausted and a radiographic abnormality is present at the symptomatic level, perhaps with pain concordant with discographic findings. Careful patient selection is the key to obtaining favorable surgical outcomes. In many cases, the goal may be a return to functionality rather than achieving a completely asymptomatic state.