Modeling mitochondrial dysfunctions in the brain: from mice to men

The biologist Lewis Thomas once wrote: “my mitochondria comprise a very large proportion of me. I cannot do the calculation, but I suppose there is almost as much of them in sheer dry bulk as there is the rest of me”. As humans, or indeed as any mammal, bird, or insect, we contain a specific molecular makeup that is driven by vast numbers of these miniscule powerhouses residing in most of our cells (mature red blood cells notwithstanding), quietly replicating, living independent lives and containing their own DNA. Everything we do, from running a marathon to breathing, is driven by these small batteries, and yet there is evidence that these molecular energy sources were originally bacteria, possibly parasitic, incorporated into our cells through symbiosis. Dysfunctions in these organelles can lead to debilitating, and sometimes fatal, diseases of almost all the bodies’ major organs. Mitochondrial dysfunction has been implicated in a wide variety of human disorders either as a primary cause or as a secondary consequence. To better understand the role of mitochondrial dysfunction in human disease, a multitude of pharmacologically induced and genetically manipulated animal models have been developed showing to a greater or lesser extent the clinical symptoms observed in patients with known and unknown causes of the disease. This review will focus on diseases of the brain and spinal cord in which mitochondrial dysfunction has been proven or is suspected and on animal models that are currently used to study the etiology, pathogenesis and treatment of these diseases

Preservation of the temporal muscle during the frontotemporoparietal approach for decompressive craniectomy: Technical note

Background In patients undergoing decompressive craniectomy, resection and detachment of the temporal muscle produces esthetic and functional damage, due to atrophy of the frontal portion of the temporal muscle in the temporal fossa. We have performed en-block temporal muscle detachment in decompressive craniectomy patients to avoid esthetic and functional damage to the temporal muscle. Methods Twenty-one patients underwent decompressive craniectomy using a frontotemporoparietal approach. Through a three-leaf clover flap skin incision, the temporal muscle was detached en-block and overturned antero-inferiorly conjoined with the frontal myocutaneous flap. A decompressive craniectomy and duraplasty were performed. A polyethylene sheet was added to prevent adherence of the temporal muscle to the dura mater. Results The decompressive craniectomy was effective in all patients. When subsequent cranioplasty was performed, the temporal muscle was easily repositioned. No complications resulted from the en-block temporal muscle detachment or the use of the polyethylene sheet. In 18 patients eligible for clinical and radiological follow-up, excellent (n=4) or good (n=14) esthetic results were detected. Chewing ability is considered normal by all patients. Conclusion Although it requires that the patient undergo two surgical procedures, en-block detachment of the temporal muscle during decompressive craniectomy allows good esthetic and functional results