Mr. J.R., a 75-year-old man with history of gastroesophageal reflux disease, hyperlipidemia and degenerative joint disease, has unintentionally lost about 15 kilos in the past year and for a few months has been experiencing lower abdominal cramps. He underwent numerous investigations for weight loss, including gastroscopy, colonoscopy, small bowel follow-through, CT scan of abdomen, chest and head, and bone scan. All were unremarkable save for an incidental left adrenal adenoma of 1.1 cm. Thyroid stimulating hormone (THS)tested normal as well. He’s been assessed by a few specialists in the past 12 months, but no specific cause of weight loss was determined.
He denies symptoms of fever, chills or night sweats. He doesn’t complain of cough, phlegm or hemoptysis. He reports occasional heartburn and difficulty with swallowing, but denies symptoms of abnormal bowel movements, rectal bleeding or melena. He’s not nauseous or vomiting. His only complaint is of lower anterior abdominal cramps and fairly persistent bilateral lower chest ache.
His past medical history is remarkable for kidney stones, benign prostatic hypertrophy, osteoporosis and left
inguinal hernia repair. He quit smoking about 20 years ago, after smoking for 45 pack-years. He doesn’t use alcohol. He’s been taking vitamin D, calcium, alendronate 70 mg weekly, lansoprazole 30 mg a day, domperidone 10 mg twice a day, docusate, clonazepam, atorvastatin 20 mg a day, and venlafaxine 37.5 mg twice a day.
The examination reveals a cachectic man with blood pressure of 148/78 mm Hg and regular rhythm. There’s no thyromegaly, bruits or lymphadenopathy. In addition to significant generalized atrophy, marked fasciculations can be seen in upper arms, shoulders, upper chest and abdominal muscles. The deep tendon reflexes are brisk (2-3+) and Babinski is equivocal. The rest of the exam is unremarkable.
A recent TSH and glucose are normal. Collagen workup is negative with ESR of 18 and negative anti-nuclear antibody.
What’s wrong with Mr. J.R.?
Mr. J.R. most likely has amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig’s disease, which affects the motor neurons. It’s of unknown cause in most patients and about 10% may have an inherited form.
The clinical course is variable but often progressive, disabling and fatal, resulting in death within 3-5 years after diagnosis in most. It affects 1 to 2 people in 100,000, with a preponderance for males, and commonly occurs in middle age and older adults. Over time, it causes increasing muscle weakness affecting walking, speech, swallowing and breathing. The ability to think, reason and remember is unaffected, however.
Weight loss in ALS occurs mostly from increased energy expenditure and, as the disease progresses, from poor dietary intake due to swallowing difficulties.
Diagnosis of exclusion
The diagnosis is often clinical, but remains one of exclusion. Investigations such as MRI of brain and spinal cord, collagen workup and electromyography are frequently required to rule out other causes and establish widespread denervation and reinnervation.
There’s no cure for ALS and treatment is mainly supportive — a multidisciplinary team is important to help maintain strength, independence, nutrition and weight, and to avoid complications. Ideally, the family physician and neurologist are supported by physical, respiratory, occupational and speech therapists, a nutritionist and a social worker. Symptomatic medications such as muscle relaxants can help to keep the patient comfortable. Riluzole has been shown to prolong survival by about 2 months and a recent study (Fornai F et al. PNAS 2008;105:2052-7) suggested that a combination of riluzole and lithium is superior to riluzole alone in slowing progression.
In addition to Lou Gehrig (New York Yankee), other famous people affected with this disease include David Niven (actor), Jacob Javits (senator), Stephen Hawkings (physicist), Eliot Porter (photographer) and Dmitri Shostakovich (composer).
This case illustrates the importance of a detailed physical. The vital clue to diagnosis was the marked fasciculations involving most of the chest and abdominal muscles that led to a full neurological exam. Mr. J.R. had seen different doctors over the past year and underwent various investigations but no one asked him to take his shirt or undershirt off to examine him fully and likely didn’t pay attention to the obvious fasciculations. It’s possible that by the time he was referred to me the disease had progressed and the muscle contractions had become easily noticeable. Presence of fasciculations doesn’t mean that a patient has ALS, but it’s suggestive and should lead to further investigations.
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