- External ophthalmoplegia (HP:0000544): Paralysis of the external ocular muscles. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:98919)
- Areflexia (HP:0001284): Absence of neurologic reflexes such as the knee-jerk reaction. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:98919)
- Anti-GQ1b antibody positivity (HP:0034122): The presence of autoantibodies (immunoglobulins) in the blood circulation that react against ganglioside Q1b. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:98919)
- Diplopia (HP:0000651): Diplopia is a condition in which a single object is perceived as two images, it is also known as double vision. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:98919)
- Horizontal nystagmus (HP:0000666): Nystagmus consisting of horizontal to-and-fro eye movements. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:98919)
- Ataxia (HP:0001251): Ataxia refers to impaired coordination of voluntary muscle movement. Cerebellar ataxia refers to ataxia due to dysfunction of the cerebellum. This causes a variety of elementary neurological deficits including asynergy (lack of coordination between muscles, limbs and joints), dysmetria (lack of ability to judge distances that can lead to under- or overshoot in grasping movements), and dysdiadochokinesia (inability to perform rapid movements requiring antagonizing muscle groups to be switched on and off repeatedly). Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:98919)
- Increased CSF protein concentration (HP:0002922): Increased concentration of protein in the cerebrospinal fluid. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:98919)
- EMG abnormality (HP:0003457): Abnormal results of investigations using electromyography (EMG). Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:98919)
- Internal ophthalmoplegia (HP:0007942): Paralysis of the iris and ciliary apparatus. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:98919)
- EEG with generalized slow activity (HP:0010845): Diffuse slowing of cerebral electrical activity recorded along the scalp by electroencephalography (EEG). Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:98919)
- Mydriasis (HP:0011499): Abnormal dilatation of the iris. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:98919)
- Photophobia (HP:0000613): Excessive sensitivity to light with the sensation of discomfort or pain in the eyes due to exposure to bright light. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98919)
- Blurred vision (HP:0000622): Lack of sharpness of vision resulting in the inability to see fine detail. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98919)
- Bulbar palsy (HP:0001283): Bulbar weakness (or bulbar palsy) refers to bilateral impairment of function of the lower cranial nerves IX, X, XI and XII, which occurs due to lower motor neuron lesion either at nuclear or fascicular level in the medulla or from bilateral lesions of the lower cranial nerves outside the brain-stem. Bulbar weakness is often associated with difficulty in chewing, weakness of the facial muscles, dysarthria, palatal weakness and regurgitation of fluids, dysphagia, and dysphonia. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98919)
- Fever (HP:0001945): Body temperature elevated above the normal range. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98919)
- Tetraparesis (HP:0002273): Weakness of all four limbs. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98919)
- Headache (HP:0002315): Cephalgia, or pain sensed in various parts of the head, not confined to the area of distribution of any nerve. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98919)
- Paresthesia (HP:0003401): Abnormal sensations such as tingling, pricking, or numbness of the skin with no apparent physical cause. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98919)
- Reduced consciousness (HP:0004372): Abnormally diminished level of attention, responsiveness, or wakefulness. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98919)
- Anisocoria (HP:0009916): Anisocoria, or unequal pupil size, may represent a benign physiologic variant or a manifestation of disease. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98919)
- Facial palsy (HP:0010628): Facial nerve palsy is a dysfunction of cranial nerve VII (the facial nerve) that results in inability to control facial muscles on the affected side with weakness of the muscles of facial expression and eye closure. This can either be present in unilateral or bilateral form. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98919)
- Abnormality of ocular abduction (HP:0011347): An abnormality involving the movement of the eye outwards. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98919)
- CSF pleocytosis (HP:0012229): An increased white blood cell count in the cerebrospinal fluid. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98919)
- Ptosis (HP:0000508): The upper eyelid margin is positioned 3 mm or more lower than usual and covers the superior portion of the iris (objective); or, the upper lid margin obscures at least part of the pupil (subjective). Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:98919)
- Vomiting (HP:0002013): Forceful ejection of the contents of the stomach through the mouth by means of a series of involuntary spasmic contractions. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:98919)
- Dysphagia (HP:0002015): Difficulty in swallowing. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:98919)
These phenotypes are associated with the disease Miller Fisher syndrome (ORPHA:98919).