Inspiratory laryngeal stridor as the main feature of progressive encephalomyelitis with rigidity and myoclonus: a case report and literature review

• Published in: BMC neurology 2022-01, Vol.22 (1), p.42-42, Article 42
• Main Authors: Yao, Qingyang, Fu, Maolin, Ren, Lijie, Lin, Caihong, Cao, Liming
• Format: Article
• Language: English
• Subjects: Airway management; Analysis; Anti-glycine receptor antibody; Antibodies; Antigens; Anxiety; Autonomic nervous system; Brain stem; Care and treatment; Case Report; Cerebrospinal fluid; Consciousness; Convulsions & seizures; Cyanosis; Diagnosis; Dysarthria; Electromyography; Encephalitis; Encephalomyelitis; Epilepsy; Gait; Glycine receptors; Health aspects; Humans; Hypoventilation; Immunological diseases; Immunomodulation; Immunotherapy; Inspiratory laryngeal stridor; Literature reviews; Magnetic resonance imaging; Male; Middle Aged; Muscle pain; Muscle Rigidity - complications; Myoclonus; Myoclonus - complications; Myoclonus - diagnosis; Neuroimaging; Panic attacks; Patients; Progressive encephalomyelitis with rigidity and myoclonus; Receptor antibodies; Respiration; Respiratory Sounds; Risk factors; Seizures; Spinal cord; Steroid hormones; Stridor; Sweating; Testing; Tumors
• ISSN: 1471-2377; 1471-2377
• DOI: 10.1186/s12883-022-02555-y

Progressive encephalomyelitis with rigidity and myoclonus (PERM) is an acute, potentially life-threatening, yet curable neuro-immunological disease characterized by spasms, muscular rigidity, and brainstem and autonomic dysfunction. The clinical features of glycine receptor (GlyR) antibody-positive PERM may be overlooked, particularly with some unusual symptoms. A 52-year-old man was admitted to the hospital for evaluation of tension headache for 20 days and mild dysarthria. These symptoms were followed by panic, profuse sweating, severe dysarthria, dizziness, unsteady gait, and paroxysmal muscle spasms. Brain magnetic resonance imaging and cerebrospinal fluid analysis were normal. The patient's condition steadily deteriorated. He repeatedly presented with rigidity, panic attacks, severe anxiety, paroxysmal inspiratory laryngeal stridor, cyanosis of the lips, and intractable epilepsy. Electromyography showed multiple myoclonic seizures, a single generalized tonic-clonic seizure, and a single generalized tonic seizure. Screening for autoimmune encephalitis antibodies revealed anti-GlyR antibodies in his cerebrospinal fluid. Immunomodulatory pulse therapy with steroids and immunoglobulin resulted in expeditious improvement of the symptoms within 2 weeks, and a follow-up at 5 weeks showed consistent clinical improvement. Our case highlights that inspiratory laryngeal stridor is an important symptom of PERM. Our observation widens the spectrum of the clinical presentation of anti-GlyR antibody-positive PERM, where early identification is a key to improving prognosis.