Autoimmune autonomic ganglionopathy with late-onset encephalopathy.
A 47-year old female presented with a 4 month history of early satiety, constipation, light sensitivity, orthostatic intolerance, siccca, and anhydrosis. Her examination revealed dilated, unreactive pupils with dry eyes and mouth but normal strength, phasic reflexes, and sensation. After 3 min of quiet standing her systolic pressure dropped 70 mmHg with a fixed heart rate of 74 bpm. Her alpha3 ganglionic AChR level was 2060 pmol/L (normal < or = 50). Orthostatic symptoms significantly improved within 10 days of completing 2.0 g/kg IVIg. Her supine norepinephrine (NE) level improved over baseline but remained low (i.e., 0.36 à 0.61 nmol/L). Persisting gut inertia prompted a trial of plasma exchange (PLEx) which restored her supine NE level (2.18 nmol/L), bowel patterns, and pupillary reactivity. Five months later, while her AAG was well controlled, she developed gait unsteadiness, confusion, horizontal and vertical nystagmus, bladder retention, and long tract motor signs. A contrast MRI head was normal. Further serum testing demonstrated binding avidity for neuronal alpha4 and alpha7 nAChRs. She responded to high-dose steroid and immunomodulation. This is the first case report of AAG presenting with antibodies directed against both peripheral and central nAChRs. It is tempting to speculate that CNS alpha4 or alpha7 antibodies may have precipitated the treatment-responsive encephalopathy.
Baker
S K
SK
Department of Medicine, Divisions of Physical Medicine & Neurology, Neuromuscular Disease Clinic, McMaster University Medical Center, McMaster University, Hamilton, Ontario L8N3Z5, Canada. bakersk@mcmaster.ca
Morillo
C
C
Vernino
S
S
D001323:Autoantibodies / Q000276:immunology*; D001324:Autoantigens / Q000276:immunology*; D020274:Autoimmune Diseases of the Nervous System / Q000150:complications / Q000276:immunology* / Q000628:therapy; D003131:Combined Modality Therapy; D004660:Encephalitis / Q000209:etiology* / Q000276:immunology; D005260:Female; D020233:Gait Disorders, Neurologic / Q000209:etiology; D005725:Ganglia, Autonomic / Q000276:immunology*; D006801:Humans; D016756:Immunoglobulins, Intravenous / Q000627:therapeutic use; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D008875:Middle Aged; D008879:Midodrine / Q000627:therapeutic use; D009638:Norepinephrine / Q000097:blood; D009759:Nystagmus, Pathologic / Q000209:etiology; D010951:Plasma Exchange; D054969:Primary Dysautonomias / Q000150:complications / Q000276:immunology* / Q000628:therapy; D011681:Pupil Disorders / Q000209:etiology; D011978:Receptors, Nicotinic / Q000276:immunology*; D013974:Thyroxine / Q000627:therapeutic use; D064569:alpha7 Nicotinic Acetylcholine Receptor
D001323:Autoantibodies; D001324:Autoantigens; D016756:Immunoglobulins, Intravenous; D007166:Immunosuppressive Agents; D008879:Midodrine; D009638:Norepinephrine; D011978:Receptors, Nicotinic; D013974:Thyroxine; D064569:alpha7 Nicotinic Acetylcholine Receptor; C579167:Chrna7 protein, human