Skin-derived precursor Schwann cell myelination capacity in focal tibial demyelination.

INTRODUCTION: Skin-derived precursor cells (SKPs) are neural crest progenitor cells that can attain a Schwann cell-like phenotype through in vitro techniques (SKP-SCs). We hypothesized that SKP-SCs could produce mature myelin and, in doing so, facilitate the recovery of a focal demyelination injury. METHODS: We unilaterally injected DiI-labeled, green fluorescent protein (GFP)-producing SKP-SCs into the tibial nerves of 10 adult Lewis rats (with contralateral media control), 9 days after bilateral doxorubicin injury (0.38 µg). Tibial compound motor action potentials (CMAPs) were followed for 57 days. A separate morphometric cohort also included a Schwann cell injection group. RESULTS: SKP-injected nerves recovered fastest in terms of electrophysiology and morphometry. SKP-SCs formed morphologically mature myelin, accounting for 15.3 ± 5.3% of the total myelin in SKP-SC-injected nerves. CONCLUSIONS: SKP-SCs are robustly capable of myelination. They improve the recovery of a focal tibial nerve demyelination model by myelinating a measured percentage of axons.

Neurofibromatous sensory neuropathy of the thigh in a 7-year-old boy.

Neuropathy is considered to be an unusual complication of neurofibromatosis 1 (NF1). Neurofibromatous neuropathy is extremely rare in the setting of paediatric age group, pure sensory mononeuropathy and NF1. The following is a description of a 7-year-old boy who presented with complains of discomfort and parasthesia on the anterior aspect of his left thigh which is an unusual mode of presentation and site of involvement. Clinical examination and imaging revealed an isolated sensory neuropathy of the left anterior femoral cutaneous nerve of the thigh secondary to plexiform neurofibromatosis involving the L1-L4 nerve roots and the anterior femoral cutaneous nerve of thigh. The main abnormality in this patient was segmental hypertrophy of the left lower limb and dilatation of left lumbar neural foramens. Subtotal excision of the neurofibromas of the anterior femoral cutaneous nerve was performed and the patient was asymptomatic at the end of 27 months (2.25 years) of followup. Although the result of treatment in this case was good, long-term followup is necessary in view of greater risk of malignant transformation and development of spinal deformity and overall long-term poor prognosis in this particular patient subgroup of NF1.

Seventeen-year follow-up of a reattachment of a nonunited anterior tibial spine avulsion fracture.

Seventeen years ago we treated a nonunited avulsion fracture of the anterior tibial spine with open reduction and pull-out wires. When the patient was 9 years old, she fell and bruised her left knee. The knee was immobilized for a month in a long cast. When she was 24 years old, she felt severe knee pain and giving way after playing tennis 1 month before her first visit to our hospital. She complained of knee pain, giving way, locking, and 15 degrees loss of knee extension. Radiographs showed a large nonunited fragment at the intercondylar eminence of the tibia. She underwent a reattachment surgery. When she was re-evaluated 17 years after surgery, she had no pain, no giving way, no locking, and no loss of knee extension. On physical examination, there was no instability. Plain anteroposterior and lateral radiographs showed a well-united fragment of the anterior tibial spine. In conclusion, the open reduction for knee pain, giving way, locking, and loss of knee extension caused by nonunion of avulsion of the anterior tibial spine yielded satisfactory results. We believe that in cases of nonunited anterior tibial spine fractures it is necessary to attempt to secure the anterior cruciate ligament in an anatomic position.

[Polyradiculoneuropathy in an adult with primitive hyperoxaluria]. / Polyradiculoneuropathie au cours d'une hyperoxalurie primitive de l'adulte.

From the age of 31 a patient began to suffer from recurrent calcium oxalate urolithiasis. Liver biopsy showed a decrease in catalytic activity of the hepatic peroxisomal enzyme alanine: glyoxilate aminotransferase (AGT), which was mistargeted from peroxisomes to mitochondria. The genetic analysis revealed a mutation of the AGT gene. At age 47 he developed end-stage renal failure and underwent hemodialysis. After 12 months of hemodialysis he presented a rapidly declining clinical condition, a decrease of the residual renal function, a livedo reticularis with painful of extremities, and shortly thereafter a general weakness, which predominated on lower limbs. Apart from renal failure, routine biological examination and CSF were normal. Nerve conduction studies and electromyography supported the diagnosis of polyradiculoneuropathy. Pathological studies revealed mixed demyelinating-axonal lesions and deposits of calcium oxalate crystals within the media and the intima of epineural arterioles. A combined liver-kidney transplant was rapidly performed. The patient's condition improved in a few months and motor signs completely disappeared.

Surgical management of cervical radiculopathy.

Cervical radiculopathy presents as pain in a dermatomal distribution. Despite conservative nonoperative therapy, a large subset of patients will require surgical intervention. Indications for surgery include recalcitrant radiculopathy despite nonoperative treatment for more than 6 weeks and progressive motor deficit or disabling motor deficit (deltoid palsy, wrist drop) prior to 6 weeks. Anterior and posterior approaches have both yielded successful results in appropriately selected patients. Anterior cervical diskectomy and fusion is the generally preferred treatment for radiculopathy when there is a significant component of axial neck pain, when the disease is centrally located, or when there is any degree of segmental kyphosis. Posterior laminoforaminotomy is an acceptable choice for lateral soft disk herniations with predominant arm pain and for caudal lesions in large, short-necked individuals.

Presurgical identification of extradural nerve root anomalies by coronal fat-suppressed magnetic resonance imaging: a report of six cases and a review of the literature.

In an attempt to depict the anatomy of the nerve roots, we obtained magnetic resonance (MR) images of the lumbar spine in the coronal plane with the frequency-selective fat-suppression technique. With this technique, extradural anomalies were identified in 20 (6.7%) of 300 patients. We report the appearance on coronal MR images of six surgically confirmed extradural anomalous nerve roots together with the myelography findings. These include type Ia, type Ib, and type 3 anomalies. These are readily recognized and allow detailed evaluation of the type of nerve root anomaly.

Massive nerve root hypertrophy in chronic inflammatory demyelinating polyradiculoneuropathy.

In the course of investigating severe, shooting leg pains in a patient with chronic inflammatory demyelinating polyradiculoneuropathy, we observed massive nerve root enlargement on magnetic resonance imaging. Clinical evaluation ruled out other possible etiologies. Lumbar laminectomy was performed in an attempt to alleviate the pain, with poor results. A review of the literature revealed that seven similar cases have been reported in the past. We report another case and a review of the literature.

Hydrocephalus in Guillain-Barré syndrome.

Hydrocephalus and pseudotumour cerebri are a rare complication of Guillain-Barré syndrome (GBS), occurring in about 4% of the cases. The high concentration of cerebrospinal fluid (CSF) protein may lead to a decreased CSF absorption in arachnoid villi. A 10-year-old boy with GBS and hydrocephalus is presented. A mechanical ventilation was required 7 days after admission and he had been on the mechanical ventilation for 6 weeks. Lumbar puncture performed on admission revealed clear CSF with an opening pressure of 15 cm H2O and no cells, a normal glucose level and a protein of 240 mg/dl. He complained of headache and diplopia 11 weeks after admission. Fundoscopy revealed papilloedema, and bilateral mild abducens pareses were also detected. Magnetic resonance imaging displayed a communicating hydrocephalus and interstitial oedema. A ventriculo-peritoneal shunt relieved the symptoms of intracranial hypertension. In GBS, serial computed tomographic scans should be performed in patients with headache and papilloedema. Hydrocephalus may develop in GBS.

Lumbosacral fusion in a patient with recurring Guillain-Barré syndrome and acute brachial neuritis.

A lumbar decompression and fusion with instrumentation was successfully completed on a patient with a history of acute brachial neuritis (ABN) and recurring Guillain Barré syndrome (GBS). Three weeks post-surgery there was a mild exacerbation of the GBS, which resolved with plasmapheresis. This case report shows that surgery may be conducted safely on a patient whose history includes GBS and ABN, without devastating neurological consequences.

Complicaciones de la traqueostomía / Tracheostomy complications

Se revisaron 52 traqueostomías realizadas entre enero de 1980 y diciembre de 1986 en el Hospital Roberto del Río correspondientes a 34 pacientes con laringitis aguda y 18 con síndrome de Guillain Barré. Se analizó edad, momento en que se realizó el procedimiento, complicaciones y duración de la hospitalización. Se observó una mediana de 1 año a 7 meses de edad para los pacientes con laringitis aguda y de 3 años 7 meses para los de síndrome Guillain Barré. En ambos grupos el procedimiento se realizó en las primeras 24 horas de ingreso. 28 pacientes presentaron alguna complicación y 16 más de una. De los 34 con laringitis aguda se complicaron 13 y de los 18 con Síndrome de Guillain Barré se complicaron 15. Las complicaciones más frecuentes fueron neumonía y atelectasia en pacientes con Síndrome de Guillain Barré; 1 enfermo con laringitis aguda severa presentó paro cardiorespiratorio intraoperatorio. La obstrucción de la cánula se observó en ambos grupos, falleciendo por esta causa uno con laringitis aguda. Se presentó estenosis traqueal en dos niños con Síndrome de Guillain Barré y uno con laringitis aguda. La traqeostomía no debería seguir siendo el método de elección en pacientes que requieran una vía aérea artificial en forma urgente y por tiempo corto, debido a que es un procedimiento con riesgo de complicaciones de gran trascendencia, y debe reevaluarse el uso de la traqueostomía en aquellos pacientes que requieran vía aérea artificial por un tiempo prolongado