Upper Airway Obstruction in the Shy-Drager Syndrome Robert H. Israel, MD, and Joseph M. Marino, M D Patients with idiopathic orthostatic hypotension (ShyDrager syndrome) may present with respiratory complications . W e recently had the opportunity to observe a patient with the Shy-Drager syndrome who developed respiratory failure due to bilateral vocal cord paresis. A 52-year-old woman was admitted for evaluation of progressive dyspnea. She noted a two-month history of increasing shortness of breath associated with wheezing but had n o other pulmonary symptoms. Two years earlier she had been diagnosed as having Shy-Drager syndrome. H e r recent manifestations included idiopathic orthostatic hypotension, fecal incontinence, urinary incontinence, dysarthria, cerebellar ataxia, and anhidrosis. H e r previous laboratory evaluation had revealed normal values for hemoglobin, white cell count, serological tests, cholesterol, triglycerides, serum thyroxine, electrolytes, serum cortisol, and urinalysis; chest roentgenograms, electrocardiogram, pneumoencephalogram, and EM1 scan were also unremarkable. O n admission she was in moderate respiratory distress and was utilizing her accessory muscles of respiration. Inspiratory wheezes were audible over the entire thorax. H e r diagnostic workup included a flowholume loop, which showed an inspiratory plateau characteristic of upper airway obstruction. Bronchoscopy revealed apposition of her vocal cords indicative of bilateral vocal cord paresis. Acute respiratory failure developed, necessitating an emergency tracheostomy. She was subsequently discharged without respiratory symptoms. The diagnosis of upper airway obstruction frequently is not considered in the differential diagnosis of a dyspneic patient. Many of these patients are misdiagnosed and treated for asthma or bronchitis. Clinical clues to upper airway obstruction include: inspiratory wheezing, stridor over the trachea, and a prolonged inspiratory phase of breathing. Physiologically the extrathoracic trachea has a tendency to narrow during inspiration because intraluminal pressure is lower than atmospheric pressure. Thus any narrowing of the extrathoracic trachea will be accentuated during inspiration. Normally the vocal cords are held apart by active contraction of the laryngeal muscles. Bilateral vocal cord paresis causes the vocal cords to rest in the midline, obstructing the From the Department of Medicine, The University of Rochester School of Medicine and Dentistry, and S t Mary’s Hospital, Rochester, NY. Accepted for publication Jan 28, 1977 Address reprint requests to Dr Israel, St Mary’s Hospital, 89 Genesee St, Rochester, NY 14611. glottic opening. Apposition of the vocal cords as seen through either direct or indirect laryngoscopy confirms the diagnosis. Shim et a1 concluded that inspiratory flow is decreased in upper airway obstruction. They found that the ratio of maximal midinspiratory flow to maximal midexpiratory flow was less than 1 in 8 of 9 patients with upper airway obstruction. Other pulmonary function tests such as the maximal breathing capacity [l] and the flowholume loop [21 are helpful in diagnosing upper airway obstruction. References 1. Jones JS, Renzetti AD Jr, Mitchell MM: The maximal breathing capacity in extrathoracic airway obstruction. Am Rev Resp Dis 106:925-927, 1972 2. Miller RD, Hyatt RE: Evaluation of obstructing lesions of the trachea and larynx by flow-volume loops. Am Rev Resp Dis 1O8:475-48 1, 1973 3. Schwartz GA: The orthostatic hypotension syndrome of ShyDrager: a clinicopathologic report. Arch Neurol 16:123-139, 1967 4. Shim C, Corro P, Park SS, et al: Pulmonary function studies in patients with upper airway obstruction. Am Rev Resp Dis 106:233-238, 1972 Cervical Myelographic Changes in Hypertrophic Interstitial Polyneuropathy Steven B. Hammerschlag, MD, Lester S. Adelman, MD, Elliott M. Marcus, MD, and Samuel M. Wolpert, iMD Hypertrophic interstitial neuropathy is usually suspected in patients with peripheral neuropathy and palpably enlarged peripheral nerves. We have recently studied an obese patient with this disease in whom the diagnosis was first suggested by a cervical myelogram. W e can find only 3 previously reported cases in which changes on cervical myelogram were described [ 1-31. A 33-year-old woman had been weak since infancy and had poorly developed musculature. Muscle biopsy at age 14 showed focal atrophy. Nerve conduction studies at age 28 demonstrated severe slowing in motor conduction of the median and ulnar nerves. Sensory examination was normal. At age 32 she developed increasing weakness of her extremities and numbness of the left leg. Examination at age 33 revealed weakness of all extremities and absent deep tendon reflexes. Plantar responses were extensor bilaterally. Pain sensation was de- From Tufts-New England Medical Center, Boston, MA. Accepted for publication Feb 1, 1977 Address reprint requests to Dr Adelman, Neuropathology Laboratory,Tufts-new England Medical Center, 17 1 Harrison Ave, Boston, MA 02111. Notes and Letters 83 Refire nces 1. Anderman F, Lloyd-Smith DL, Mavor H, et al: Observations on hypertrophic neuropathy of DGjkrine and Sottas. Neurology (Minneap) 12:712-724, 1962 2. Bellon EM, Kaufman B, Tucker ME: Neuropathy: plain film and myelagraph ic changes. Radiology 103:3 19-3 2 2, 1972 3. SyrnondsCP, Blackwood W: Spinal cord compression in hypertrophic neuritis. Brain 85:251-260, 1962 The Inhibitory Effect of Multiple Scleiosis and Control Sera on Certain My - elin- Catabolizing Jmzymes Iris Fletchcr Norstrand, MD, PhD, and Paul Druck, BS Cervical myelograrn (anteroposterior view) showing multiple bilateral intradural extramedullary Jillirrg dejicts dae to the thickened n e r z e roots (arron7s). creased distal to the midcalves and midpalms. Vibratory sensation was diminished distally. Motor and sensory nerve conduction velocities were slow. A cervical myelogram showed bilateral intradural, extramedullary filling defects at multiple levels (Figure) and minimal enlargement of the intervertebral foramens. A biopsy of the left sural nerve showed a decreased axonal population with “onionskin” proliferation of the endoneurial fibrous tissue. Both the light and electron microscopical features were consistent with hypertrophic interstitial neuritis. The patient was but peripheral nerves could not be palpated because of her obesity. 84 Annals of Neurology Vol 2 No 1 July 1977 Many investigators believe that the initial event in demyelination in multiple sclerosis is digestion of basic protein by acid proteinase prior to any breakdown of lipids, or before any focal immunological reaction occurs [ 1-41. Accordingly, we postulated that multiple sclerosis might be due to lack of an inhibitory substance to this o r some other myelin-catabolizing enzymes. To examine this hypothesis it was necessary to show that body fluids (serum or spinal fluid) from control patients have an inhibitory effect, whereas body fluids from patients with multiple sclerosis either have no inhibitory effect or cause activation or induction of the respective enzymes. Sera from 26 patients with multiple sclerosis (21 faradvanced and 5 early cases) and from 26 controls ( 10 normal adults and 16 patients with various other neurological conditions) were tested for the presence or absence of an inhibitor or activator of the neural enzymes acid proteinase, arylsulfatase, and cerebroside galactosidase, obtained from homogenates of normal human brain. Similarly, spinal fluid (both unconcentrated and concentrated ten times by dialysis) was examined in 8 patients with multiple sclerosis and 10 controls solely for its effect o n acid proteinase. For each enzyme studied, the enzyme reaction was run alone using 0.002 M phosphate buffer, p H 7.4, instead of the appropriate body fluid. Four separate determinations were made concomitantly, substituting serum and spinal fluid from controls and from patients with multiple sclerosis for From the Neurology Service, Brooklyn Veterans Administration Hospital, Brooklyn, N Y . Accepted for publication Dec 21, 1976. Address reprint requests to Dr Norstrand, Neurology Service, Brooklyn Veterans Administration Hospital, 800 Poly P1, Brooklyn, NY 11209.