La diagnosi di Sclerosi Laterale Amiotrofica(SLA): 2009

The diagnosis of ALS per se may be challenging since there is no single diagnostic test for the disease with the exception, today, of finding a mutation in defined genes as SOD1, TDP-43, etc. The World Federation of Neurology (WFN) developed workable, internationally acceptable diagnostic criteria that would enhance clinical and research studies in the field of ALS. The revised El Escorial criteria edited in 2000 (Brooks et al., 2000) state that to establish the diagnosis of ALS, a combination of LMN and UMN signs with evidence of spread is required. Four cardinal regions have been defined and spread of signs from region to region is essential for the character of ALS. On clinical ground it is seldom possible to establish an early diagnosis of ALS that needs then to be supported mainly by neurophysiological testing. In clinical practice the differential diagnosis of ALS is extensive because symptoms and signs of both LMN and UMN are encountered in a large and varied group of disorders, both neurologic and systemic. Furthermore, today two areas deserve particular attention in the process of diagnosis: cognitive impairments once considered rare or uncommon occur in a large percentage of ALS patients. Careful neuropsychological testing needs indeed to be completed for possible overlapping forms with fronto-temporal dementia (FTDL). Furthermore, the most intriguing area is related to genetics. Since 1993 and the definition of SOD1 mutations in familial ALS, other genes have been discovered and the impact of genetics on ALS diagnosis is today critical. An accurate understanding of the familial contribution to ALS would have a significant impact on the diagnosis of individuals both at an early age, prior to the onset of symptoms or at the first appearance of symptoms. In practice, the diagnosis of any is made by a process of clinic logic that is defined both by the characteristics of the disease itself and by an intuitive process of decision making in which the clinician weights the clinical evidence according to an experiential model built from clinical experience gained over time. In ALS, this concept must be revisited because the recent impact of new genetic discoveries requires to the clinician a continuous update for the genotype-clinical phenotype coupling. New genetic acquisitions can unquestionably speed early diagnosis of ALS.