Motoneuronal death is a major feature in many neuromuscular diseases. As a result of the remarkable ability of motor axons to sprout and to regenerate, the extent of motoneuronal loss often does not become clinically apparent until the loss is well advanced. This discrepancy is particularly striking in chronic, slowly progressive disorders in which surviving motoneurons have ample time to expand their innervation field. In those conditions, motor unit number estimation (MUNE) can be particularly valuable in gauging disease severity, disease progression and treatment response.In this review, we will briefly describe the commonly used MUNE methods. Their applications in neuromuscular diseases and the findings from these studies will be described in detail. BASIC CONCEPTS IN MUNESOnly in terminal stages of motor neuronal or axonal diseases when a few motor units remain is it possible to count all the ABSTRACT: Motor unit number estimation (MUNE) is an electrophysiological method designed to quantify motor unit loss in target muscles of interest. Most of the techniques are noninvasive and are therefore well suited for longitudinal monitoring. In this brief review, we describe the more commonly used techniques and their applications in amyotrophic lateral sclerosis, poliomyelitis, spinal muscular atrophy and hereditary sensorimotor neuropathies. Findings in some of these studies offer important pathophysiological insights. Since conventional electrophysiologic methods are not sensible measures of motor neuronal loss, MUNE could play a potentially important role in the diagnosis, monitoring of disease progression and response to treatment in neuromuscular diseases in which motor unit loss is a major feature.RÉSUMÉ: Estimation du nombre d'unités motrices dans les maladies neuromusculaires. L'estimation du nombre d'unités motrices (ENUM) est une méthode électrophysiologique pour quantifier la perte d'unités motrices dans les muscles étudiés. La plupart des techniques non effractives sont donc appropriées pour la surveillance longitudinale. Dans cette courte revue, nous décrivons les techniques les plus fréquemment utilisées et leur application dans la sclérose latérale amyotrophique, la poliomyélite, l'atrophie musculaire spinale et les neuropathies sensitivomotrices héréditaires. Les observations provenant de ces études fournissent des indices physiopathologiques importants. Étant donné que les méthodes électrophysiologiques conventionnelles ne constituent pas une mesure sensible de la perte de neurones moteurs, l'ENUM pourrait jouer un rôle important dans le diagnostic, la surveillance de la progression de la maladie et la réponse au traitement dans les maladies neuromusculaires où la perte d'unités motrices est un élément important.Can. J. Neurol. Sci. 2008; 35: 153-159 THE CANADIAN JOURNAL OF NEUROLOGICAL SCIENCES 153

This male patient presented with a scrotal abscess and urinary obstruction. The patient’s history included a perineal abscess and the development of urethrocutaneous fistulae (watering-can perineum). He underwent multiple debridement procedures without resolution. During the fifth debridement for Fournier’s gangrene, a biopsy revealed invasive squamous cell carcinoma. The patient was bedridden because of the large mass, a wide en bloc resection with lymphadenectomy and reconstruction was performed revealing a large (22 cm) squamous cell carcinoma originating from the urethra. He also received palliative chemoradiotherapy and hip hemiarthroplasty. Unfortunately, he succumbed to the disease. Given the recognized relationship between inflammation and the development of cancer, it is important to entertain a differential diagnosis of cancer, especially with erosive infections. This case report highlights the all too common late presentation of urethral cancer. Interestingly, despite correction of the bedridden state with palliative surgery, the patient did not perceive an improvement in quality of life based on the FACT-G questionnaire.

Objective: Eosinophils may affect each stage of tumour development. Many studies have suggested that tumour-associated tissue eosinophilia (TATE) is associated with favourable prognosis in some malignant tumours. However, only a few studies exist on TATE in central nervous system (CNS) tumours. Our recent study exhibited eosinophils in atypical teratoid/rhabdoid tumours (AT/RTs), pediatric malignant CNS tumours with divergent differentiation. This study examines eosinophils in pilocytic astrocytomas (PAs). Methods: The study included 44 consecutive cases of patients with PAs and no concurrent CNS inflammatory disease. Results: We found eosinophils in 19 (43%) of 44 PAs (patient age range, 0.5-72 years). Eosinophils were intratumoural and clearly distinguishable. The density of eosinophils was rare to focally scattered. PAs containing eosinophils were located throughout the CNS. Furthermore, eosinophilic infiltration was identified in 18 (62%) of 29 pediatric (age range, 0.5-18 years) PAs but only 1 (7%) of 15 (p < 0.001, significantly less) adult (age range, 20-72 years) PAs. Eosinophilic infiltration showed no significant differences between PAs with and without MRI cystic formation, surgical procedures, or PAs with and without leptomeningeal infiltration. In comparison, eosinophils were absent in 10 pediatric (age range, 0.5-15 years) ependymomas (or anaplastic ependymomas). Conclusions: These results suggest that eosinophils are common in pediatric PAs but rare in adult PAs. This difference is probably related to the developing immune system and different tumour-specific antigens in children. TATE may play a functional role in the development of pediatric PAs, as well as some other pediatric CNS tumours such as AT/RTs. RÉSUMÉ: Infiltrats éosinophiles dans les astrocytomes pilocytiques de l'enfant et du jeune adulte. Objectif: Les éosinophiles peuvent influencer chaque stade de l'évolution tumorale. Selon plusieurs études, l'éosinophilie tissulaire associée à certaines tumeurs malignes (ÉTAT) comporterait un pronostic favorable. Cependant, peu d'études sur l'ÉTAT de tumeurs du système nerveux central (SNC) ont été réalisées. Nous avons démontré récemment la présence d'éosinophiles dans des tumeurs tératoïdes/rhabdoïdes atypiques (TT/RA), des tumeurs malignes du SNC chez l'enfant avec différentiation divergente. Cette étude examine la présence d'éosinophiles dans les astrocytomes pilocytiques (APs). Méthode: Nous avons étudié 44 patients consécutifs atteints d'un AP, sans maladie inflammatoire concomitante du SNC. Résultats: Nous avons retrouvé des éosinophiles dans 19 (43%) des 44 AP. L'âge des patients atteints de ces tumeurs allait de 0,5 à 72 ans. Les éosinophiles étaient intratumoraux et clairement identifiables. Leur densité était variable, parfois rares ou en foyers dispersés. Les AP contenant des éosinophiles étaient localisés dans tout le SNC. De plus, une infiltration par des éosinophiles a été observée dans 18 (62%) des 29 AP chez les patients d'âge pédiatrique (écart de 0,5 à 18 ans), mais...