Laryngospasm as preceding symptom of amyotrophic lateral sclerosis

Abstract

A 62-year-old man presented with paroxysmal sensation of suffocation, each time lasting for about 10 s. They were not triggered by body position, physical exercise, or sleep, and there was no associated dysphagia, dysphonia, cough, stridor, or pyrosis. Clinical examination was normal. A diagnosis of laryngospasm was evoked. Electromyography (EMG), including bulbar exploration, brain and cervical spine MRI, direct laryngoscopy (performed in absence of clinical symptoms), and esophagogastroscopy were normal. Laryngospasms persisted after gastric antisecretory medication. CAG repeat length in the androgen receptor gene, in search for Kennedy’s disease, was normal. One year after laryngospasm onset, progressive distal left arm weakness occurred. Clinical examination revealed left thenar, hypothenar, and interossei muscle weakness and atrophy, fasciculations in both upper limbs and tongue, generalized deep tendon hyperreflexia, left-sided Babinski sign, hypernasal voice, brisk jaw-jerk, and emotional lability. EMG showed reduced compound motor action potential amplitude in the left arm without conduction block on nerve conduction studies, with normal F-wave and sensory nerve conduction studies. Electromyographical exploration showed diffuse fibrillations and positive sharp waves at rest in the left upper limb, both lower limbs, and paravertebral muscles, together with large, long and polyphasic muscle unit potentials during muscle contraction. EMG of bulbar muscles was normal. Positron emission tomography with fludeoxyglucose F 18 showed a severe hypometabolism of bilateral temporal and frontal lobes and anterior cingular region. A diagnosis of amyotrophic lateral sclerosis (ALS) was made in presence of El Escorial criteria. Functional pulmonary exploration was normal. Frequency of laryngospasm remained stable the first year following ALS diagnosis. Laryngospasm is clinically defined as a sudden-onset sensation that air cannot be moved in or out, usually followed by inspiratory stridor, due to a rapid and forceful contraction of the laryngeal sphincter [1]. It sometimes results in loss of consciousness making urgent tracheostomy necessary [2]. A gastroesophageal reflux disease is found in 80% of patients with laryngospasm [3]. ALS is defined by progressive degeneration of upper and lower motor neurons. One-third of ALS patients present with bulbar symptoms [4]. In a large cohort of 44 ALS patients with initial bulbar symptoms, none had isolated laryngospasm [5]. Laryngospasm is reported in 2% of ALS patients in early clinical stage, but seems to be more frequent in later stages of the disease [6, 7]. Kennedy’s disease (KD) is characterized by lower motor neuron dysfunction with predominant bulbar involvement. Laryngospasms have been described in 47% in a series of 49 KD patients [6]. All of these patients had bulbar involvement and 65% had pyrosis. Laryngospasm was observed in all stages of KD and there was no increase in frequency of laryngospasm in later stages of the disease. In two-thirds of the patients with laryngospasm and associated pyrosis, laryngospasm was reduced by gastric antisecretory and prokinetic drugs. Our presented patient is the first case of laryngospasm preceding ALS diagnosis. Laryngospasm was probably related to ALS since there were no arguments for G. Fourcade (&) G. Castelnovo D. Renard P. Labauge Department of Neurology, CHU Nimes, Service des Explorations Fonctionnelles du Systeme Nerveux, Hopital Caremeau Place du Pr Debre, 30029 Nimes Cedex 9, France e-mail: n.fourcade@wanadoo.fr