Sindromi compressive dei nervi cutanei alla fascia della gamba

Abstract

IntroduzioneLe sindromi canalicolari rappresentano un quadro patologico caratterizzato da segni neurologici o vascolari legati alla sofferenza di un nervo in un suo tratto anatomico. La pratica sportiva, sempre più comune anche in età avanzata, e le posture assunte per attività lavorative sono le due cause che più hanno portato a un aumento di frequenza di questa patologia.Generalmente si tratta di compressioni legate al passaggio del nervo in un tunnel osteo-fibroso inestensibile o di una compressione estrinseca per tumori o varianti anatomiche. Appartengono alla fase di neuroaprassia e questo chiarisce come la sintomatologia non sia sempre correlabile al danno e al quadro anatomo-patologico. In questo le lesioni iniziali sono di tipo vascolare con prevalente interessamento del sistema venoso subepineurale e conseguente stasi, edema, incremento dei fe-LO SCALPELLO (2011) 25:74-78 ABSTRACT -ENTRAPMENT SYNDROMES OF PERIPHERAL NERVES IN THE LEGEntrapment syndromes are a group of peripheral nerves disorders characterized by neurological signs or vascular symptoms, due to chronic injury to the nerve as it travels from one body segment to the next. The two leading causes of this pathology are work postures and sports activities, the latter more and more common also in the elderly population. Nerve entrapment is generally caused by localized mechanical pressure from inelastic structures such as an osseoligamentous tunnel or by estrinsic compressions due to neoplasms or anatomic variations. Nerve damage is classified as neurapraxia and symptoms don't often correlate with nerve damage or histological features. Repetitive injury to a nerve may initially result in microvascular (ischemic) changes in perineural venous system (vasa nervorum) leading to endoneurial edema formation, increase in intraneural pressures and further interferenceof endoneurial microcirculation with subsequent ipoxia. Injury to the outside layers of the nerve (myelin sheath) leads to perineural fibrosis and, in more advanced stages, focal segmental demyelination related to sclerosis at the area of compression. The diagnosis is made with a thorough clinical examination, allowing to identify the nerve involved in this painful condition and the area of compression and to define the severity of the disease. EMG and, rarely, MRI or echography complete the diagnostic pathway. Operative treatment is reserved for those patients in whom conservative treatment has been unsuccessful. Timing for surgery is dependent on knowing the different anatomical entrapment sites and their specific clinical presentations. Surgical treatment in the early stages of the disease is preferable, before chronic ischemic lesions lead to permanent sensory and motor impairment.