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Introduction We present 72 VEPs showing absence, or severe slowing, of the potentials on stimulation of either eyes, in patients from the hospital for children Robert Reid Cabral, and adults from the Rehabilitation Center and our private rooms in Santo Domingo. All studies were performed on a Cadwell Sierra, stimulating both eyes(L/R), or Right vs. Left eyes, Although studies included Mo-Mf, Right Ro-Mf and Left Lo-Mf electrodes, only midline responses are quoted for this paper. Methods Patients awake, bottle feeding or even soothers allowed, thermostat at 74 °F, room lighting off for 100 stimuli, mainly flashes run. Causes are divided to 1. Infections. Meningitis, Encephalitis, Zikca microcephaly. 2. Pre and Neonatal disturbances: asphyxia, eclampsia, 3. Squint defects, nistagmus. 4. Multiple Sclerosis. 5. Acute syndromes, CVA, trauma. 6. Optic Neuritis, glaucoma. 7. Insufficient indications i.e. unknown causes: Evoked responses are divided into absent, or slow if delays are prolonged. Results For the entire 72 case sample, Bilateral stimulation evoked 9 absent and 10 slow responses, while the left eye stimuli showed 32 absent and 9 slow responses: right eye stimulation showed 33 absent and 7 slow responses: mean amplitude 10.49 uV. Normal remaining bilateral (L/R) stimuli evoked average delays of N75, P109, N147. Left eye stimuli evoked average responses at N77, P108, N139, while responses for right eye stimulation occurred at N79, P113, N146. From this 72 case sample, the first cause of absent responses corresponds to acute lesions such as CVA or trauma with 8/8 studies i.e. 100%. The next causes are shown in the following decreasing order. 2nd Optic Neuritis with 9/10 for 90% 3rd Multiple Sclerosis with 7/8 (87%). 4th Pre and Perinatal disorders occurring in 9/11 for 81%. 5th Infections such as meningitis in 10/13 with 76%. 6th Finally Strabic and Nistagmic syndromes with 9/13 come last at 69%. Conclusion VEP become abnormal with unilateral complete or partial loss in large cerebral lesions occurring in Cerebrovascular Accidents, or trauma as well as in the five other etiologies, specially in MS thus helping in its diagnosis. We note that delays are frequently abnormal while stimulating both eyes, thus damage is more extensive than expected in the optic or visual pathways. In this presentation we demonstrate that control testing shows improvement in 3 cases. |
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