Lesões olfatórias pós-traumáticas / Post traumatic olfactory lesions

OBJETIVO: Documentar a incidência de lesões traumáticas do nervo olfatório, assim como a etiologia traumática; correlacionar as lesões do nervo olfatório com achados radiológicos (lesões cranianas e intracranianas) e estudar lesões múltiplas de nervos cranianos. MÉTODOS: Vinte e quatro pacientes admitidos no Serviço de Emergência da Santa Casa de Misericórdia de São Paulo com lesão traumática do nervo olfatório foram incluídos. Os pacientes foram divididos em três grupos, de acordo com o escore da escala de coma de Glasgow (ECG): trauma leve (ECG de 13 a 15), moderado (ECG de 9 a 12) e grave (ECG de 3 a 8), assim como em diferentes graus de lesão do olfatório, como hiposmia, anosmia e parosmia, distribuição quanto a gênero, presença de fraturas, lesões intracranianas, fístulas liquóricas e mecanismo de trauma. RESULTADOS: Dos 24 casos, 15 lesões ocorreram em conjunto com outros nervos cranianos e em nove casos houve lesão exclusiva do nervo olfatório. O atropelamento foi a causa mais comum de lesão do nervo olfatório de forma isolada, assim como nas lesões de múltiplos nervos. Hematomas extradurais foram as lesões intracranianas mais frequentes e a ausência de fraturas predominou nos indivíduos estudados. CONCLUSÃO: Neuropatia traumática do olfatório deve ser pesquisada na admissão do paciente (quando possível), sobretudo quando houver evidência de traumas frontais ou occipitais.

OBJECTIVE: To register the incidence of the traumatic lesions to the cranial nerves and its etiology; to correlate the lesions to the radiological ndings (cranial and intracranial) and study multiple cranial nerve lesions. METHODS: Fifty-four patients admitted to the Emergency Service of Santa Casa de Misericórdia de São Paulo Hospital have been studied and lesions to the different cranial nerves were described. All patients were submitted do radiographic exams, computed tomography, and, when necessary, magnetic resonance imaging. The patients were divided into 3 groups according to the Glasgow Coma Scale (GCS) in: mild trauma (GCS: 13 to 15), moderate (GCS: 9 to 12) and severe (GCS: 3 to 8). RESULTS: Posttraumatic single nerve lesion was more frequent seen on olfactory, facial and oculomotor nerves.Running over was the main cause of these lesions (single nerve and multiple nerves). Contusions and extradural hematomas were the most frequent intracranial lesions. CONCLUSION: Traumatic cranial neuropathy occurs frequently and must be searched on the patient admission, because it can surgical decompression may necessary, such as decompression of the optic or facial nerves.

Expression of odorant receptor genes on the olfactory epithelium following olfactory nerve disconnection / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To constitute the animal model of unilateral olfactory nerve transection and observe the expression level and distribution of odorant receptors.</p><p><b>METHODS</b>Thirty-two rats were divided into two groups: the olfactory nerve transection group (20) and the control group (12). The former group received the operation to transect the left olfactory nerve following the left olfactory bulb was exposed under microscope and the latter group did not give any disposal. At every stage of five days, two weeks, four weeks and six weeks after the operation, five rats from the nerve transection group and three from the control group were anaesthetized simultaneously, and olfactory epithelium were taken out after transcardial perfusion, then paraffin imbedding. Coronal sections were sliced for HE staining to observe the thickness changes of the olfactory epithelium, and for in situ hybridization (ISHs) to investigate the expression of olfactory receptor genes (Olr287, Olr226, Olr1493 and Olr1654) in the epithelium, also to evaluate the changes of the expression level and location of the selected receptors during the regeneration of olfactory epithelium.</p><p><b>RESULTS</b>HE staining showed that 5 days after the operation cell quantity and thickness of the olfactory epithelium decreased obviously, which increased gradually 2 or 4 weeks after operation. After 6 weeks' recovery, the thickness of the epithelium could reach the control level. The pattern of cell staining by ISH showed a specific spatial distribution along the anteroposterior (AP) and dorsoventral (DV) axis. Evidence suggested that odorant receptors were distributed in continuous and multiple overlapping bands in the normal or nerve transected-recovered epithelium rather than in the conventionally accepted three or four zones. The data also demonstrated that the distribution of sensory neuron types, as identified and defined by odorant receptor expression, was restored to normal or nearly so by 6 weeks after operation. Likewise, the numbers of probe-labeled neurons in the nerve transected-recovered had an obvious decrease 5 days after olfactory nerve transection. Reactive cells (x(-) +/- s) of Olr1493 in the operated side was (53.9 +/- 19.9), compared with (419.0 +/- 21.2) in the unoperated side, there was statistic significance between them (t = 63.960, P < 0.01). Reactive cells increased gradually according to the regeneration of the epithelium, and were nearly equivalent to the normal side 6 weeks later without significant differentiation (t = 2.600, P > 0.05), according to the absolute positive cells in the operated and unoperated side of (417.8 +/- 32.4) and (445.3 +/- 10.0) respectively.</p><p><b>CONCLUSION</b>The regeneration of the sensory neurons and receptors, both the number and the distribution, can recover to normal after olfactory nerve transection.</p>