[Report of two cases of anti-LGI1 autoimmune encephalitis in Mexico]

Background: Anti-LGI1 encephalitis is characterized by a pattern of inflammation that predominantly affects the limbic system It is part of the autoimmune encephalitis that attack neuronal surface antigens. It is characterized by the triad of subacute dementia, faciobrachial dystonic crises, and hyponatremia, presenting an excellent response to immunotherapy. The aim of this article is to describe the clinical evolution and functional outcome at 6 months of two patients with anti-LGI1 encephalitis using clinical cases.

Clinical cases

Case 1: 62-year-old man with 8-week symptoms manifested by changes in mood, disorientation, and focal motor seizures. Case 2 A 72-year-old woman with a 5-month evolution of rapidly progressive dementia, hyponatremia and bitemporal hyperintensities on MRI. In both, due to clinical suspicion, acute dual immunotherapy with steroid and immunoglobulin was given with substantial improvement. Subsequently, the existence of anti-LGI1 antibodies in cerebrospinal fluid was confirmed. Although both patients received a dose of rituximab during their hospitalization, only the patient in the first case continued biannual doses of rituximab. The second patient was not initially considered to continue long-term immunomodulatory treatment and experienced a relapse.

Conclusions

These clinical vignettes present the reader with the classic characteristics of this disease. This can facilitate its recognition and timely initiation of treatment, improving the functional prognosis of patients.

[Parkinson-dementia and amyotrophic lateral sclerosis association (complex of Guam). Diagnostic challenge, Mexican patient]

Background

The Amyotrophic Lateral Sclerosis-Parkinsonism-Dementia Complex (ALS-PDC) was first described in the islands of Guam. This pathology presented its peak incidence in the 1950s. Due to the rarity of the association, we report a clinical case with this complex. The objective was to describe the nosological and pathogenic implications of these neurodegenerative disorder, since they are not frequent to find in our population.

Clinical case

We present a case of Latinoamerican origin who initially manifested systemic symptoms of more than 6 years of evolution, with subsequent cognitive alterations. Later, patient began with gait disturbances and motor symptoms suggestive of parkinsonism with atypical data and data of motor neurone disease (MND). More studies were carried out and confirmed findings compatible with upper and lower motor neuron involvement. A mutation in the POLG gene was observed, related to mitochondrial depletion syndrome.

Conclusion

Despite the knowledge of this association, it is an entity whose clinical diagnosis could be very difficult to achieve. In addition, molecular mechanisms have not been fully identified, the most common genes related to Parkinsonism and ALS have been excluded, and even attempts to locate the locus were made, without achieving accurate results. Unfortunately, being a neurodegenerative disease, the prognosis is fatal, with no disease-modifying treatment.