Amyotrophic Lateral Sclerosis (ALS), also known as a motoneuron disease, is a  progressive neurodegenerative disease that attacks the motoneurons or that is the nerve cells that transmit the commands for movement from the brain to the muscles, in this way causing atrophy and progressive weakening to the point of paralysis.   ALS is a disease with an inauspicious prognosis and of which the cause is still unknown: currently a cure does not exist.

In Italy, on average three new cases of ALS are discovered each day and approximately six patients for every 100,000 inhabitants are counted.  ALS is a neurological disease that is relatively unknown.

HOW TO SURVIVE WITH ALS

ALS is a chronic disease that profoundly changes ones life.  The person affected cannot face it alone: he needs other people in order to move, to express himself, to dress, to eat and to breath.  Family, friends, co-workers, doctors, nurses, assistance personnel and the patient himself all together can become precious and indispensable resources.

Amyotrophic Lateral Sclerosis (ALS), is a degenerative disease of the central nervous system with a progressive course that begins in adulthood.
ALS manifests with a progressive motor deficiency regarding the limbs, the trunk and on a muscular level affecting the phonatory (vocal cords) and deglutition (swallowing).  The onset begins on average during the seventh decade of life (60-70 years). 
It has a majority of frequency in males. The incidence is of approximately 2-2.5 cases per 100,000 inhabitants/year, without relevant differences in western countries (Traynor et al, 1999; Chiò et al, 2001).
The average medical duration of the illness is approximately 2.5 years (Chiò et al, 2002) and death generally occurs due to insufficient respiration or respiratory complications of dysphagia. 

Pathogenic hypothesis

Currently, the cause of ALS is unknown.  Approximately 5-10% of the cases are Familial, usually with autosomal dominant inheritability.  Regarding the Sporadic cases, the pathogenic hypotheses are varied. (Mitsumoto et al, 1998). Excitotoxicity due to the accumulation of L- glutamate is hypothesised. The proof of excitotoxicity type damage in ALS is for the most part indirect (increase of glutamate in the cerebrospinal fluid liquor, reduction in the absorption of the glutamate in the motor cortex and in the medulla).
Moreover, there are indications that in ALS patients there is an alteration in the oxidative balance (reduction in the activity of the glutathione reductase enzyme; increase in the formation of nitrogen oxide [NO] apart from NO synthase), with an intercellular accumulation of free radicals.  The oxidative damage may be the ultimate common path that determines the motoneuron death as a consequence of the effects of the diverse mechanisms of the aetiopathogensis.  Diverse indications exist regarding the involvement of the neurofilaments (NF) in the pathogenesis of ALS (accumulation of NF in SOD-1 transgenic mice, deletion of the gene by the heavy chains in the NF in some cases of sporadic ALS).
The controlled case studies completed to date (which compare patients afflicted with ALS with healthy controls in order to observe the frequency of risk factors) have not identified certain risk factors for ALS beyond the aforementioned citations of male and advanced age. Among the factors which demonstrated to be significant include mechanical and electrical traumas to the limbs or spinal column, residence in an agricultural zone, the participation in agonistic sporting activities, physically demanding work, an elevated consumption of milk, prolonged contact with metal, insecticides or herbicides and some professional activities (agriculture, farming, welding and tanning).
Recently, an excess number of ALS cases were revealed among the American military that were deployed during the first Gulf War; even being demonstrated that there was a significant increase in risk of ALS development among those who returned from the Gulf with respect to the military not sent to the area of operation, a clear pathogenic correlation was not identified (Haley, 2003; Horner et al, 2003).


ALS and sporting activity

(1) Regarding specific sporting activity, the available data is very fragmented.  In particular, there are two orders of information:  
Anecdotal cases, often largely covered by mass media, which historically carry the case of the young American baseball player Lou Gehrig who was struck by ALS in 1939 at the age of 35 and passed away approximately 2 years later. Furthermore, the small but interesting cluster of 3 American football players that played contemporaneously for the San Francisco 49ers in 1964 and developed ALS in the 80s is often reported. (Norris,1990). This cluster was connected to a fertiliser, Milorganite, which was widely used on the training field of the team. A characteristic of this fertiliser is that it is composed, in part, from foundries waste and as such, is extremely rich in metallic residue.  This observation was not successively confirmed.

(1) Study of death certificates
Preliminary data based on the mortality of a cohort of approximately 24,000 professional and semi-professional football players (Belli, 2003) revealed the presence of a significant excess in deaths from ALS during the period of 1960-1996 with respect to the number expected in the Italian population (ISTAT (State Statistics Institute) data on death certificates) ( cases observed 8, cases expected 0.69; SPMR [Standardized Proportional Mortality Ratio] 11.58, i.c. 95% 6.72-19.98). The excess amount which results to be particularly significant is among the age inferior to 60 years.
The results of this study are of itself extremely indicative of the existence of a pathogenetic relationship between ALS and football. Nevertheless, some methodological problems are felt: (1) the inaccuracy in the death certificates; (2) the uncertainty relative to the completeness of the cohort of football players used;  (3) the impossibility of discrimination between an effect of football in itself and a generic effect of trauma/micro-trauma in the genesis of ALS. To remedy the first two criticisms, a valid alternative would be the study of incidences on the base of a cohort of risks defined in an extremely rigorous manner. 

2) Retrospective Study cohort on incidence. 
Methods
An epidemiological retrospective study was implemented on professional football players (Series A and B) in order to identify the presence of any eventual excess of risk of ALS.
Determination of the study cohort  
The members of football players for the teams in Series A and B during the pre-selected period  were initially identified from two sources (1) the archives of the Panini company, which for more than 40 years has produced figures regarding football players; (2) the archives from the National  Welfare and Assistance Office for Workers in the Entertainment Business (ENPALS), of which since 1973 is obligatory for all professional football players to enrol.
All playing members of the football teams in Series A and B during the period from 1970-2001 were also included in the cohort of the study.  The years 2002-2003 were excluded  by taking into consideration the average diagnostic delay of 1-2 years from the onset of the disease to the diagnosis which is constantly revealed in the literature (Chiò 1999).
The players born outside of Italy for which it was impossible to have an adequate
follow-up regarding the status of life or the eventual onset of ALS were excluded.

Identification of the cases.
The cases of ALS were identified through a series of current sources:
a) death certificates
b) research in the discharge archives of the principal ALS Centres of Italy;
c) information from non secular press and the internet;
d) spontaneous declarations from the subjects themselves, their families or other sources.