Takao Kitamura

Petrous apex cholesterol granuloma treated via the endoscopic transsphenoidal approach

SummaryNumerous surgical approaches have been used to treat petrous apex cholesterol granulomas. They are usually treated via the transtemporal- or middle fossa approach; some are managed endoscopically. We present a patient treated by the endoscopic transsphenoidal approach and review the literature.

Common diseases mimicking lumbar disc herniation and their treatment

1Department of Neurosurgery, Chiba Hokuso Hospital, Nippon Medical School, Inzai-city, Chiba 270-1694, Japan. 2Department of Neurosurgery, Kushiro Rosai Hospital, Kushiro-city, Hokkaido 085-0088, Japan. 3Department of Neurosurgery, Nippon Medical School, Bunkyo-ku, Tokyo 113-8603, Japan. 4Department of Neurosurgery, Teikyo University, Itabashi-ku, Tokyo 173-8606, Japan. 5Department of Neurosurgery, Iwate Medical University, Morioka-city, Iwate 020-8505, Japan.

Peroneal nerve entrapment neuropathy induced by playing the drum

Dear Editor, A 15-year-old boy presented with pain and motor weakness in the right leg. Ten months earlier, he had complained of gradually worsening pain in the right lower leg that was exacerbated by walking and standing. He was unable to walk more than 100 m and experienced intermittent claudication. He had a history of playing the drum every day for some years, and used his right foot to operate the bass drum during these sessions. Upon admission, the patient exhibited pain in the lateral aspect of the right lower leg and dorsal foot (visual analogue scale [VAS], 7/10), hypoesthesia of the base of the right first and second toes, and motor weakness of the right ankle dorsiflexion (manual muscle test, 4/5). The circumference of his right lower leg was smaller than that of the left leg (Fig. 1a). Although results of the straight leg raising test and Kemp test were both negative, Tinellike sign at the right peroneal tunnel was positive. Nerve conduction studies (NCS) showed no conduction block in the peroneal nerve (PN). Based on these symptoms, peroneal nerve entrapment neuropathy (PNEN) was diagnosed. Analgesic therapy and a 2-month rest from playing the drum failed to improve the patient’s symptoms. Therefore, we performed microsurgical decompression for right PNEN under local anesthesia. Briefly, a skin incision measuring 3 cm was made along the PN around the fibular neck and the superficial fascia was exposed. We observed that the PN was compressed by the fibrous band between the peroneus longus and the soleus [8], and by the contraction of the peroneus longus and the soleus with ankle dorsiflexion and flexion (Fig. 1b-d). After dissection of the fibrous band, we observed bulging of the PN (Fig. 1e). After surgery, the patient was able to walk without pain or motor weakness. His postoperative course was uneventful and there was no recurrence 1 year later. Previous reports have documented nerve entrapment points and reported good surgical outcomes [2, 4, 6–8]. The PN is subject to static compression around the peroneal tunnel through the following entrapment sites: intermuscular septum [5], peroneal muscle fascia [3], confluence of the origin of the soleus and peroneus [4], entrance of the fibular tunnel [2], fibrous band surface of the deep head of the peroneus longus, and the fibrous band deep to the peroneus longus [4]. Good surgical outcomes have been described in such cases; however, the pathological mechanism underlying PNEN is unclear. Fabre et al. [6] documented dynamic compression of the bilateral PNEN by the fibrous arch due to well-developed leg muscles in two athletes. The authors speculated that repeated flexion and extension of the knee resulted in irritation of the PN. However, dynamic causes of PNEN have not otherwise been reported. We similarly speculate that repetitive extension and flexion of the ankle while stamping the bass * Takao Kitamura taka-kitamu@nms.ac.jp

Deep Decompression of the Lateral Femoral Cutaneous Nerve Under Local Anesthesia

OBJECTIVE Meralgia paresthetica is a mononeuropathy of the lateral femoral cutaneous nerve (LFCN) caused by compression around the inguinal ligament. We report a surgical alternative for the treatment of meralgia paresthetica under local anesthesia and its outcomes. METHODS We operated on 12 patients with unilateral meralgia paresthetica whose age at surgery ranged from 62 to 75 years. The mean postoperative follow-up period was 19 months. Microsurgical deep decompression of LFCN was performed with the patient under local anesthesia. Clinical outcomes of surgical treatment were assessed based on the patients most recent follow-up visit and were classified into 3 categories: complete, partial, or no relief of symptoms. Symptoms of pain or numbness in the anterolateral part of the thigh were evaluated, using a visual analog scale, before surgery and after surgery, i.e., at the most recent follow-up visit. RESULTS All patients reported symptom improvement: complete relief in 9 patients (75%) and partial relief in 3 patients (25%). In the 3 patients with partial relief, the remaining symptoms did not affect their daily living. Overall, the visual analog scale scores were significantly improved in all patients (P < 0.05), and no patient experienced postoperative recurrence of their symptoms at the time of the last follow-up visit. CONCLUSIONS Symptoms of meralgia paresthetica can resemble those of a lumbosacral disorder. Microsurgical deep decompression under local anesthesia produces good surgical outcomes. The use of local anesthesia contributes not only to reduction of pain during surgery but also eliminates excessive surgical procedures and reduces the duration of hospital stay.

Aneurysm Tears Caused by an Aneurysm Clip Springing from the Clip Applier

We experienced two cases in which aneurysm clips sprang from the applier. In case 1, a subdural haematoma from a ruptured anterior cerebral artery aneurysm was detected. When the clip was opened for final positioning, it suddenly sprang from the applier and ruptured the aneurysm. In case 2, the clip suddenly sprang from the applier as the surgeon opened the applier to clip an unruptured anterior cerebral aneurysm. These accidental phenomena are rare but dangerous. We present these cases to help prevent similar occurrences in the future. Video recordings of actual procedures can point to potential mechanisms and help reduce the incidence of this complication.

An Unruptured Aneurysm Coexisting with an Infundibular Dilatation: A Case Report

BACKGROUND Infundibular dilatation (ID) is a funnel-shaped enlargement of the origin of cerebral arteries. The coexistence of an aneurysm and ID is relatively rare. Patients with IDs are rarely followed up. However, some IDs have been reported to develop into aneurysms with subsequent rupture. Here we report on a case of an aneurysm that coexisted with ID of the posterior communicating artery. CASE PRESENTATION A 51-year-old woman underwent magnetic resonance imaging (MRI) to check for aneurysms and other problems. MRI revealed an unruptured aneurysm of the right internal carotid artery, for which the patient was admitted to our hospital. Three-dimensional computed tomographic angiography revealed an aneurysm, which protruded outward, and ID of the posterior communicating artery, which protruded inward. A right pterional craniotomy was performed with aneurysm clipping. The postoperative course was uneventful. In this report, we demonstrate operative views of the aneurysm and ID with the use of neuroendoscopy. CONCLUSION ID can develop into a true arterial aneurysm and potentially rupture. Therefore, we need to observe the patients with IDs carefully, particularly in young women.