Cases reports: Two females from different families, 34 and 16 years old, who started at puberty with distal weakness in lower limbs and difficulty in walking. The youngest had a history of parental consanguinity. The oldest also developed symptoms of cerebellar ataxia. Both patients had joint hypermobility. After physical exercise, both showed increased serum levels of creatine phosphokinase, but only one of them showed increased lactate. Both electroneuromyography showed motor neuropathy, predominantly in lower limbs, with axonal and demyelinating pathophysiology, with probable superimposed pre-ganglionic involvement. Both genetic tests showed homozygous pathogenic variation in COQ7 gene, described as Chr16:19.067.667, which leads to methionine substitution and impaired protein traduction. Discussion: Primary COQ10 deficiency is a heterogeneous group of mitochondrial disorders caused by defects in proteins involved in COQ10 biosynthesis. It’s inheritance usually is autosomal recessive. Mutations in 10 genes directly involved in coenzyme Q10 synthesis and collectively named “COQ genes” have been identified. Clinical spectrum may overlap encephalomyopathies, ataxia, neuromyopathy, spastic paraplegia and even impairment of another organs. Only four COQ7 deficiency patients have been reported so far. In addition, cases reported here are related with a new variation in COQ7 gene. All reported COQ7 deficiency patients have asian ancestry, which is not the case of patients related here. Some improvement can occur by COQ10 supplementation, which was initiated in both cases. Conclusion: The diagnosis of primary COQ10 deficiency is limited by factors like rarity, heterogeneous phenotypes and unavailability of genetic testes, which favors under or misdiagnosis. Discovery of new cases and mutations can increase our knowledge about this condition, make possible the diagnosis, consequently look for dysfunction of other organs and try a specific treatment.

Case report: Woman, 34 years old, with paresis that started four years ago during pregnancy, predominantly distal in the lower limbs and progression to the upper limbs. No involvement of cranial nerves and sensitivity. Initially considered a diagnosis of Myasthenia Gravis and clinical gain was observed with the use of pyridostigmine. After a few months, the patient’s symptoms recurred with asymmetric flaccid tetraparesis, predominantly in the lower limbs, associated with global areflexia and oral immunosuppressive therapy was initiated, with improvement. Electroneuromyography with normal sensory nerve conduction studies, but reductions in amplitudes in proximal compound muscle action potentials, with markedly reduced persistence in F-wave studies of the four limbs. Diffuse neurogenic changes were observed on exertion and activities such as positive sharp waves, fibrillation, fasciculations and myokymia at rest. Repetitive nerve stimulation at 3Hz without changes. A hypothesis of multifocal motor neuropathy (MMN) was then made. Treatment with intravenous immunoglobulin was performed, with significant recovery of symptoms. Discussion: MMN is a rare disease (prevalence of 0.6 per 100,000 individuals), with a predominance in men and a mean age of onset around 40 years. The differential diagnosis includes motor neuron disease and other demyelinating neuropathies. It is immune-mediated by antianglioside antibodies (anti-GM1), but they are not identified in all patients and may be present in other neuropathies. It is defined by muscle weakness predominantly distal, asymmetrical, predominantly in the upper limbs, slowly progressive, associated with reduced deep reflexes in the affected regions. The main electrophysiological characteristic is the presence of motor nerve conduction blocks (CB) outside the usual sites of compression. Conclusion: The finding that CB presents in patients with MMN suggests that nerve conduction should be extensively studied in every patient with a lowermotor-neuron syndrome to identify patients who might respond favorably to immunomodulating treatment.

Introduction: Posterior reversible leukoencephalopathy syndrome is an acute/subacute clinical-radiological syndrome characterized by headache, changes in consciousness, seizures, focal neurological deficits, visual deficits and that may be preceded by uncontrolled blood pressure in the day before. It does not commonly occur concomitantly with prolonged infectious conditions. The most typical imaging finding is white matter edema in the posterior cerebral hemispheres. Treatment is based on adequate control of blood pressure and epileptic seizures, as well as metabolic and electrolyte control. The prognosis in most cases is excellent with significant improvement and complete reversal over days to weeks. Case report: Female, 37-year-old, after one month of underwent an endoscopic retrograde cholangiopancreatography was hospitalized due to a perirenal abscess, and treatment with antibiotics was initiated. During this treatment, she developed a sudden onset of bilateral amaurosis, continuous horizontal nystagmus, mental confusion, right upper limb weakness and hyperreflexia, in addition to an epileptic seizure and fencing response posture requiring intravenous phenytoin. Brain tomography demonstrated hypodensity in the occipital hemispheres and magnetic resonance imaging identified signal alteration in the white matter diffuse without diffusion restriction compatible with posterior reversible leukoencephalopathy syndrome. She evolved with adequate control of blood pressure and epileptic seizures, progressive improvement in visual acuity and muscle strength, until he returned to normality 10 days after the onset of symptoms. The antiepileptic drug was suspended, and she was discharged with antihypertensive medication. Conclusion: Posterior reversible leukoencephalopathy syndrome is an important differential diagnosis in conditions of sudden deficits and seizures, especially in this infectious context, because it is a reversible clinical condition with a good prognosis.