Sir,

Post-infectious demyelination is not uncommon in children and can present with myriad of symptoms depending on the topographical localization.  We would like to report a case of acute-onset facial motor tics as a presenting feature secondary to demyelination. 

An 11-year-old healthy boy presented to us with a short history of fever, headache and sore throat.  He was treated with five days of oral antibiotics for probable throat infection.  His inflammatory markers and Antistreptolysin O titer were normal, and throat swab was sterile.  He represented five weeks later with acute-onset facial motor tics worsening for last one month.  In addition, he complained of mild headaches.  There was no history suggestive of Obsessive Compulsive Disorder (OCD) or Attention Deficit Hyperactivity Disorder (ADHD).  His neurodevelopment was age-appropriate, and there was no evidence of developmental regression. 

On examination he was well in himself and apyrexial.  He had very florid orofacial simple motor tics in the form of 'tongue protrusion' and 'eye blinking'.  His neurological examination was unremarkable.  His full blood count, electrolytes, C-reactive protein, liver function tests, Antistreptolysin O titer, Anti DNAse B, thyroid functions, copper, ceruloplasmin, auto-antibodies, throat culture and cardiac echocardiogram were normal.  Magnetic resonance imaging (MRI) brain showed high signal lesions in the cerebellar peduncle and pons on T2-weighted image \[[Figure 1](#F1){ref-type="fig"}\] with normal T1-weighted and diffusion-weighted (DW) images suggestive of demyelination.  There was no post-gadolinium enhancement.  Cerebrospinal fluid was normal.  Polymerase chain reaction for herpes and other viruses was negative. 

![ T2W MRI brain showing an area of demyelination at the junction of right middle cerebellar peduncle and pons](AIAN-16-292-g001){#F1}

He was treated with intravenous methylprednisolone and almost became symptom-free by the end of five days. 

A tic is a sudden, rapid, recurrent, non-rhythmic, stereotyped motor movement or vocalization.\[[@ref1]\] Depending upon the complexity, tics can be categorized into simple and complex types.  Clinically, tics can manifest as motor or phonic presentations.  A motor tic can be tonic, clonic or dystonic.  Using the Diagnostic and Statistical Manual of Mental Disorders, 4^th^ Edition Text Revision (DSM-IV-TR) criterion tics can be categorized into Transient Tic Disorder, Chronic Tic Disorder, Tourette syndrome and Tic disorder not otherwise specified.\[[@ref2]\] Our case had simple motor orofacial tics of dystonic form, and qualified at presentation for the DSM-IV-TR category of Transient Tic Disorder.  Absence of vocal tics and co-morbidities such as ADHD and OCD and the duration of tics less than one year ruled out Tourette syndrome in our case at the time of presentation.\[[@ref2]\] The acquired causes of tics include autoimmune, toxic, degenerative and vascular etiologies.\[[@ref3]\] Acquired demyelination in children can present in several ways.  Usual clinical features include encephalopathy, motor, sensory, brain-stem or ocular symptoms.\[[@ref4]\] Extrapyramidal movement disorders have hardly been reported,\[[@ref5]\] and there is only one published case report of phonic tics as a manifestation of Multiple Sclerosis in a 34-year-old lady, and motor tics have never been reported as a presenting feature.\[[@ref6]\] While Acute Demyelinating Encephalomyelitis (ADEM) can present with tics, our case did not have encephalopathic features and the typical MRI findings seen in ADEM.\[[@ref7]\] Our case highlights a very rare manifestation of demyelination, and underscores the importance of neuroimaging in the evaluation of acute-onset movement disorders including tics in children.