18F-FDG PET/CT and functional MRI in a case of crossed logopenic primary progressive aphasia

Primary progressive aphasia is a clinical syndrome caused by a neurodegeneration of areas and neural networks involved in language, usually in the left hemisphere. The term "crossed aphasia" denotes an acquired language dysfunction caused by a lesion in the hemisphere ipsilateral to the dominant hand. A case is presented on a 75-year-old right-handed woman with a logopenic variant of primary progressive aphasia with word-finding difficulties of 2 years onset. The ¹⁸F-FDG PET/CT showed right temporoparietal hypometabolism. A functional MRI scan was performed during a verb naming task in order to characterise language lateralisation patterns. A similar activation pattern was observed in both hemispheres, with less activation than expected in bilateral inferior frontal gyrus. These findings support that logopenic variant of primary progressive aphasia should not be considered as a neurodegeneration starting in the left brain hemisphere, but as a syndrome characterised by asymmetric neurodegeneration of brain regions and neural networks involved in language.

[Meralgia paraesthetica: a report on a series of 140 cases]

INTRODUCTION

Meralgia paraesthetica is a pathology that is frequently seen in visits to extra-hospital neurology services. Nevertheless, the diagnosis, treatment and prognosis of this condition remain somewhat unclear.

PATIENTS AND METHODS

A retrospective study was conducted involving 140 patients. Data were collected concerning demographic aspects, clinical picture, diagnostic study, aetiology, treatment and progression.

RESULTS

There was a predominance of males, with a mean age of 54 years. The mean follow-up time was 25 months. The symptoms that were reported were as follows: numbness, burning pain, tingling or prickling in the nerve territory. Hypaesthesia was the most frequent sign found in the examination. History of another compressive neuropathy was present in 13.6% of patients. The diagnosis was based on the patient record and the neurological examination. The neurophysiological study and complementary tests were reserved for atypical cases. The most common causation was spontaneous and only three cases were found to be secondary to a structural lesion. A third of the patients were receiving pharmacological treatment. Although the clinical picture was benign, in most cases it tended to become chronic. Patients treated pharmacologically did not show a significant improvement in comparison to those who were not given treatment. The most important data for forecasting improvement of the clinical picture were the identification and correction of the factors precipitating compression of the nerve.

CONCLUSIONS

Meralgia paraesthetica is a frequent, benign pathology but with a tendency to become chronic that responds poorly to pharmacological treatment. It is important to identify and correct mechanical factors and only in exceptional cases is it secondary to a structural lesion.

[Post-traumatic supraorbital neuralgia: a benign condition]

INTRODUCTION

Supraorbital neuralgia has only recently been described. Most of the cases reported involve patients suffering from chronic idiopathic neuralgias that are difficult to treat and sometimes require surgery to release the nerve. We present our experience in patients with a variant of this neuralgia which has a known causation, is commonly seen and has a benign prognosis.

CASE REPORTS

We studied five patients, four females and one male, with a mean age of 55 years (range: 29-69 years). They had all suffered direct banal traumatic injury to the frontal region due to different causes. Four of them developed continuous, piercing or burning-type pain; three of them had paroxysmal pain and one had itching. There were no autonomic manifestations. All of them were found to be abnormally sensitive in the affected area, with tactile hypaesthesia, hyperalgesia or allodynia and a positive Tinel's sign. Neuroimaging tests were normal. Two patients were treated with gabapentin and amitriptyline. One was treated with an anaesthetic blockade, which afforded temporary relief. Three of them received no treatment at all. After one year of follow-up, all of them had improved and three were no longer in pain, although sensory alterations persisted in all cases.

CONCLUSIONS

Post-traumatic supraorbital neuralgia is a frequent condition, although it is probably underdiagnosed. It has its own characteristic clinical and developmental features that distinguish it from idiopathic supraorbital neuralgia. Progress is usually good and it responds favourably to symptomatic treatment, if needed.

[Brachial presentation of spinal pseudochoreoathetosis. The result of proprioceptive information being processed in parallel]

INTRODUCTION

The term pseudochoreoathetosis is used to refer to the choreoathetoid movements that are produced by alterations in the proprioceptive sensitivity due to damage it has suffered at some point along its course. Proprioceptive sensitivity is considered to go up as far as the cortex along the posterior cords of the spinal cord, which means that if they are injured in the cervical region there should be a sensory deficit in both the upper (UL) and lower limbs (LL).

CASE REPORTS

We describe five cases of transverse myelitis with localised cervical injury that selectively and mainly affected the posterior cords of the spinal cord. In the five patients there was selective involvement of the proprioceptive sensitivity in the UL respecting the LL and pseudochoreoathetoid movements of the limb that has been deafferented for proprioceptive sensitivity. The dissociation between the UL and the LL occurs because the spinocerebellar and spinocervical tracts take the proprioceptive information from the LL in parallel to the posterior cords, which receive the proprioceptive sensitivity from the UL.

CONCLUSIONS

At present, the most widely accepted physiopathological mechanism explaining pseudochoreoathetosis consists in a failure in the integration of the sensory-motor afferences in the striatum, which causes faulty sensory-motor integration at this level and gives rise to pseudochoreoathetosis.