“Icing” The Eyes

R. Rajarajan

Consultant Neurologist, Kauvery Hospitals, Tennur, Trichy

Case Presentation

A 65-year old lady was referred to our neurology clinic with drooping of her right upper eyelid. There was no diplopia, despite the ptosis being present for 2 weeks. There was no history suggestive of fatiguability. In her medical history she had hypertension and dyslipidemia; medication was telmisartan 20 mg, ecosprin 75 mg and rosuvastatin 20 mg once a day. She had no personal or family history of neurological or autoimmune disorders. On examination, we found that she had ptosis of her right eyelid and overactivity of her frontalis muscle. There was no misalignment or restriction of movement of her extraocular muscles, and she had no bulbar weakness; all other cranial nerves were normal. She had no other focal neurological signs.

Laboratory investigation found a normal full blood count and normal kidney and liver function. ESR, CRP and Thyroid functions were normal. We made a provisional diagnosis of Ocular myasthenia gravis and decided to carry out an ice pack test to affirm our conclusion. We, therefore, applied an ice pack to the patient’s eyelid for 2 min, which improved her ptosis by more than 2 mm. Notably, the improvement was temporary, lasting approximately 7 min. Electrodiagnostic tests of patinet’s right abductor pollicis brevis, right orbicularis oculi, and right nasalis muscles were normal; Anti-acetylcholine receptor antibody was negative. The patient wImprovement of a ptotic eyelid with local cooling is a quick and easy way of differentiating neuromuscular from peripheral nerve or muscle disorders causing ptosis. Ptosis due to neuropathy of the third nerve usually presents with a limitation of upward, downward, and inward gaze, as well as pupillary involvement. Headache with isolated mydriasis-with no extraocular movement impairment-can be the first presentation of a compressive third nerve palsy because the autonomic fibres have a peripheral distribution and are the first to be damaged in the case of an expansive lesion. Ptosis is a feature of Horner’s syndrome, but it usually presents with miosis and anhidrosis. Myogenic ptosis is rarer and, although ophthalmoplegia is possible, does not improve with cooling.as treated with oral pyridostigmine 60 mg – clinical improvement, noticeable after 30 min, lasted nearly 4 h.

Improvement of a ptotic eyelid with local cooling is a quick and easy way of differentiating neuromuscular from peripheral nerve or muscle disorders causing ptosis. Ptosis due to neuropathy of the third nerve usually presents with a limitation of upward, downward, and inward gaze, as well as pupillary involvement. Headache with isolated mydriasis-with no extraocular movement impairment-can be the first presentation of a compressive third nerve palsy because the autonomic fibres have a peripheral distribution and are the first to be damaged in the case of an expansive lesion. Ptosis is a feature of Horner’s syndrome, but it usually presents with miosis and anhidrosis. Myogenic ptosis is rarer and, although ophthalmoplegia is possible, does not improve with cooling.

The ice pack test also helps to guide clinical decision-making while waiting for the results of complementary investigations. It may be particularly useful when electrodiagnostic test was normal with a negative Ach receptor antibody test-as in our patient. Ice pack test is a highly sensitive and specific test for ocular myasthenia gravis. The combination of unilateral eyelid ptosis and a positive ice pack test will then confirm the diagnosis.