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Morquio syndrome is a hereditary mucopolysaccharide disorder presenting with an abnormality of the craniocervical junction from childhood. We describe an adult patient who presented with Morquio syndrome who had subglottic narrowing of the airway, restrictive pulmonary disease, and mild mitral regurgitation and trivial aortic regurgitation. The anesthetic management of this patient for atlantoaxial stabilization is presented.

We report a patient with Parkinson’s disease undergoing craniotomy for a brain tumor, who had clinically adequate hypnosis at a very low concentration of isoflurane. While the raw EEG showed low-voltage slow electrical activity, the EEG analyzer of the monitor displayed high burst suppression ratios. The role of intracranial pathology and drug therapy as possible causes of the low anesthetic requirement for adequate hypnosis are discussed. This report also draws attention to the possibility of erroneous analysis of burst suppression by EEG modules.

To the Editor: A 17-year-old boy of 160 cm height and 30 kg weight, diagnosed with Hallervorden–Spatz syndrome (HSS), also known as pantothenate kinase-associated neurodegeneration (PKAN), presented as severe opisthotonus, retrocollis, deteriorating intelligence level, thoracolumbar spine scoliosis, and tongue dystonia and was scheduled for brain magnetic resonance imaging (MRI) under general anesthesia. On preanesthesia examination, his heart rate was 127 bpm, respiratory rate 16/min, blood pressure 80/45 mm Hg, and oxygen saturation 95 % on room air. A loading dose of 1 lg/kg dexmedetomidine (Dexem; Themis Medicals, India) was infused over 15 min. With this, posturing and rigidity disappeared and the Ramsay sedation score (RSS) reached 5. Dexmedetomidine infusion was continued at a rate of 0.5 lg/kg/h using an MRIcompatible infusion pump (Perfusor; Space B/Braun, Germany) during MR imaging that lasted 1 h. Oxygen was administered through a face mask. He was hemodynamically stable throughout the procedure. An RSS of 2 was reached and opisthotonus posturing and rigidity reappeared 2 h after stopping the infusion. This case report highlights successful use of dexmedetomidine as a sole sedative agent for MRI in a patient with HSS. HSS is a rare autosomal recessive disorder caused by pantothenate kinase-associated neurodegeneration 2 (PKAN2) gene mutations resulting in accumulation of iron in the brain. The disease is also called neurodegeneration with brain iron accumulation (NBIA) [1]. Presenting features of HSS include progressive generalized dystonia involving the oromandibular muscles, rigidity, and choreoathetoid movement [1]. Airway management is critical during anesthesia in these patients. Oromandibular dystonia results in impaired swallowing, malnourishment, and high risk for pulmonary aspiration. Involvement of the pharyngeal muscles results in breathing difficulty and dynamic airway obstruction. These patients develop contractures and joint stiffness, including the jaw and cervical spine, leading to difficult airway. Associated mental retardation renders preoperative airway assessment difficult. Airway problems necessitate careful postoperative monitoring. MRI studies demand a quiet patient for better image quality. Severe dystonia necessitated sedation/general anesthesia in our patient. In a previous case report, volatile anesthetic was used to sedate a child with HSS, but postoperatively the patient developed airway obstruction requiring emergency intubation [2]. In our patient, we chose dexmedetomidine to provide sedation without respiratory depression [3]. As dystonia completely disappeared and an RSS of 5 was achieved after a bolus infusion of dexmedetomidine, we continued dexmedetomidine infusion during the MR imaging. Dexmedetomidine, by alpha-2 adrenergic modulation, induces prolonged nonREM sleep. As muscle atonia has been described during non-REM sleep, patients receiving dexmedetomidine infusion tend to be in a relaxed state with reduced muscle tone [4]. This mechanism could have suppressed the dystonia in our patient. Although propofol has been used in such patients, we avoided propofol as it causes dystonic reactions and opisthotonus [5]. Dystonia suppression by B. Madhusudhana Rao M. Radhakrishnan (&) Department of Neuroanesthesia, National Institute of Mental Health and Neuro Sciences, Bangalore 560029, Karnataka, India e-mail: mrks1974@gmail.com