The Biochemistry Behind Cognitive Decline: Biomarkers of Alzheimer's Disease

Alzheimer's disease (AD) is the most prevalent type of dementia. Pathologically, the disease is marked by neurofibrillary tangles (NFT), which are aberrant accumulations of the tau protein that develop inside neurons, and extracellular plaque deposits of the amyloid β peptide (Aβ). These pathological lesions are present in the brain before the beginning of clinical manifestations. However, despite advancements in the comprehension of AD pathophysiology, timely and accurate clinical diagnosis remains challenging. Therefore, developing biomarkers capable of detecting AD during the preclinical phase holds enormous promise for precise diagnosis since detecting the disease early is crucial because it enables interventions when treatments may be more effective. This article intends to provide a comprehensive review of AD biomarkers, discussing their significance, classification, and recent developments in the field.

[Calcified cerebral hydatid cyst. Report of a case]

The cerebral localization of the hydatid cyst is still rare (1 to 4% of the cases). The calcified cerebral hydatid cyst is exceptional. We report one case collected in our department. It is about a patient of 28 years old, that the case histories consist in convulsive attacks since the age of 8 years old, hospitalized because of a left hemiparesis with progressive installation. The cerebral computerized tomography showed a right parieto-occipital that is largely calcified. During the operation, a calcified hydatid cyst discovered with various daughter vesicles and a cerebral gliosis, the latter has been extracted entirely. The evolution has been favourable with improvement of the left hemiparesis. The calcified hydatid cyst of brain is still exceptional, its symptomatology is the same as the safe CHC, but it poses some diagnostic and therapeutic problems.

[Suboccipital tuberculosis: a case report]

Suboccipital tuberculosis is an uncommon localization of Pott's disease. The gravity results from the neurological and life threatening risk. We report a case of suboccipital tuberculosis in a 22-year woman who survived. She was given an anti-tuberculosis antibiotic regimen due to pulmonary and pericardal involvement. The patient interrupted her treatment after four months and was admitted six months later for torticolis and spastic tetraplegia without sphincter disorders. Standard x-rays and MRI of the head confirmed suboccipital Pott's disease. Transcranial evacuation was performed and the patient was again given anti-tuberculosis antibiotics. The clinical course was favorable with definitive recovery 45 days later. The patient continued the antibiotic regimen for nine months. An orthopedic supporting device was worn for nine months. The diagnosis of suboccipital tuberculosis can be confirmed on MRI. Appropriate treatment is a subject of debate between exclusive orthopedic or combined orthopedic and surgical treatment. Prognosis depends on the neurological deficit, early diagnosis and prompt treatment.

[Sphenotemporal aneurysmal bone cyst. A new case and review of the literature]

Aneurysmal bone cysts (ABC) are benign tumors of the bones, formed by multiple cysts filled with blood and eroding the bone. They are rarely located at the skull. We report a case of a right temporal ABC in a 5-year-old girl. On admission, the physical examination showed a tough and fixed tumor, with no inflammatory signs nor vascular characteristics. The neurological examination was normal. Imaging studies showed an heterogeneous extracerebral mass, eroding the temporal bone and the greater wing of the sphenoid bone. The treatment consisted in an extensive tumor resection, associated with reconstructive surgery. The outcome was uneventful (follow-up 27 months). We underline the pathogenetic, diagnostic and therapeutic features of this condition.

[Multiple cerebral hydatic cysts of cardiac origin. A case report]

The hydatic cyst is a pathology observed in developing countries. Multiple cerebral localizations with a cardiac origin are exceptional and are sometimes diagnosed only after onset of complications. We present the case of a 22-year-old male student: the diagnosis of multiple cerebral hydatic cysts caused by rupture of a cardiac hydatic cyst was established after an episode of ischemia of the limbs with cerebral hemorrhage induced by heparin. One year later, the clinical situation consisted in intracranial hypertension, hemiplegia and convulsive seizures. We observed no cardiac symptoms. The brain CT showed 9 hydatic cysts and echocardiography showed a myxomatous cystic tumor. Abdominal CT detected renal and splenic hydatic cysts. The patient underwent total ablation of the cerebral and abdominal cysts and made a full recovery. After surgical removal of the cardiac cyst, the patient has been lost to follow-up. Cerebral hydatidosis of cardiac origin is highly exceptional and, due to nonspecific symptomatology, may go undiagnosed. In general, prognosis is good in case of a cerebral localization but the cardiac localization is associated with high mortality.

[Intracranial meningioma in an infant. Report of a case]

We report a case of a benign temporal meningioma in 1 month old infant. The diagnosis was revealed by atypical seizure. The physical exam was normal. We underline the epidemiological, clinical and prognostic aspects of this condition.

The effects of temperature, humidity, photoperiod and weight of the engorged female on oviposition of Boophilus annulatus (Say, 1821)

At a constant temperature of 25 degrees C and 84% relative humidity the pre-oviposition period of Boophilus annulatus was 2-5 days (mean 2.7 days) and the oviposition lasted 11-17 days (mean 15 days). The peak egg laying occurred 1-6 days (mean 3.5 days) after the start of oviposition. The daily egg output was 135 (range 90-190) and the total egg production was 2004 (range 1432-2664). Light had no significant effect on oviposition. There was a highly significant correlation between the weight of the engorged female and the total egg yield (r = 0.78; P less than 0.01). The pre-oviposition and oviposition periods were not influenced by the weight of the engorged females. The relative humidity (25, 62, 93%) had no effect on the oviposition, but the temperature (16, 25, 35 degrees C) had a significant influence on it. The pre-oviposition and oviposition periods increased with the decrease of temperature. The course of oviposition was similar at 25 and 35 degrees C, with a peak occurring within a few days of the start of egg-laying, followed by a gradual decline. At 16 degrees C, the egg production curve was flat, without a peak. However, the total number of eggs produced was not significantly different at the three temperature regimes.