Fourth nerve palsy presenting with trochleodynia

Abstract

Trochleitis is an uncommon disorder that is defined as inflammation of the superior oblique tendon trochlea apparatus and is characterized by pain, point tenderness over the trochlea, and/or localized swelling [1, 2]. In absence of clear findings suggestive of inflammation on blood test and radiology, this characteristic orbital pain around the trochlea with tenderness and exacerbation during upward gaze is called a primary trochlear headache or trochleodynia [3, 4]. In addition to the characteristic pain, trochleodynia can be accompanied by migrainous headache, ptosis, and conjunctival injection [2–4]. However, trochleodynia presenting with diplopia is rare. Herein, we report a patient with fourth nerve palsy associated with primary trochlear headache. A 29-year-old man presented with binocular vertical diplopia and left-side periocular pain for 4 days, which occurred after 1 day of migrainous headache. The migraine disappeared spontaneously with supportive care. However, the concurrent dull headache, periocular pain, and diplopia were not improved by analgesics or triptans. He denied diurnal variation of these symptoms. The periocular pain was exacerbated by eye movements, especially elevation. Examination of external eye did not show abnormal findings such as conjunctival injection, chemosis, proptosis, and periorbital edema. Painful tenderness was evoked by compression over the trochlear area (a score of 8 on the visual analogue scale; Fig. 1a). He had no medical history of hypertension or diabetes mellitus. He also denied any head trauma or ocular operation history. The vital signs were stable. His head was tilted rightward (Fig. 2) and hypertropia of the left eye (2 prism diopter, PD) was increased on adduction (3 PD), depression (3 PD), and leftward head tilt (4 PD; Fig. 2). The fundus photography shows no abnormal ocular torsion. These findings were most consistent with left trochlear nerve palsy. Other findings of neurological and neuro-ophthalmological examinations were normal. The results of laboratory evaluations, including autoimmune disease and vasculitis, were normal. There were also no remarkable findings that could explain his neurological deficits on MRI of the brain and orbit (Fig. 3). We diagnosed him as having primary trochlear headache with trochlear nerve palsy. The patient was injected with 3 mg of dexamethasone and 3 mg of methylprednisolone (final volume, 1 ml) targeted to the symptomatic trochlea (Fig. 1b). Periocular pain and tenderness were resolved within 48 h, and the diplopia gradually improved over several days. Our patient showed trochlear nerve palsy with focal tenderness in the trochlea, which was responsive to local steroid injection. Trochleodynia is a pain originating in the trochlear region that is felt in the upper-inner angle of the orbit and typically exacerbates upon elevation or palpation [4, 5]. Trochleitis is a syndrome of inflammatory K. J. Lee S.-H. Jeong (&) A. Y. Lee J.-M. Kim Department of Neurology, Chungnam National University Hospital, 640, Daesa-dong, Joong-ku, Daejeon 301-721, Korea e-mail: mseaj@hanmail.net