The frontal lobe (from the Greek lobos) constitutes one of the regions of the brain located at the front of the cranium.

Position. The frontal lobe is located in the front of the brain, below the frontal bone. It is separated from the other lobes by different grooves:

• The central sulcus, or Rolando sulcus, separates the frontal lobe from the parietal lobe;
• The lateral sulcus, or Sylvian sulcus, separates the frontal lobe from the parietal and temporal lobe.

Main structure. The frontal lobe is one of the regions of the brain. The latter is the most developed part of the brain and occupies most of it. It is made up of neurons, the cell bodies of which are located on the periphery and form the gray matter. This outer surface is called the cortex. The extensions of these bodies, called nerve fibers, are located in the center and form the white matter. This internal surface is called the medullary region (1) (2). Numerous furrows, or cracks when they are deeper, distinguish different areas within the brain. The longitudinal fissure of the brain allows it to be separated into two hemispheres, left and right. These hemispheres are connected to each other by commissures, the main one of which is the corpus callosum. Each hemisphere is then divided, through the primary sulcus, into four lobes: the frontal lobe, the parietal lobe, the temporal lobe and the occipital lobe (2) (3).

Secondary and tertiary structures. The frontal lobe has secondary and tertiary grooves, making it possible to form convolutions called gyri. The main frontal lobe gyri are:

• the central gyrus,
• the superior frontal gyrus,
• the middle frontal gyrus,
• the inferior frontal gyrus.

The cerebral cortex is associated with mental and sensitivomotor activities, as well as the origin and control of skeletal muscle contraction. These different functions are distributed in the different lobes of the brain (1).

The frontal lobe essentially groups together motor functions, and more particularly voluntary ones. One distinguishes in particular the primary motor field located at the level of the precentral gyrus, as well as the area of ​​Broca, zone associated with the speech. The frontal lobe also has regions for information transformation (2) (3).

Certain pathologies can develop in the frontal lobe and affect the central nervous system. The causes are varied and can in particular be of degenerative, vascular or tumor origin, certain pathologies

Stroke. Cerebrovascular accident, or stroke, occurs when a cerebral blood vessel is blocked, such as the formation of blood clots or the rupture of a vessel4. This pathology can impact the functions of the frontal lobe.

Head trauma. It corresponds to a shock at the level of the skull which can cause brain damage, in particular at the level of the frontal lobe. (5)

Multiple sclerosis. This pathology is an autoimmune disease of the central nervous system. The immune system attacks the myelin, the sheath surrounding nerve fibers, causing inflammatory reactions. (6)

Brain tumor. Benign or malignant tumors can develop in the brain, especially in the frontal lobe. (7)

Degenerative cerebral pathologies. Certain pathologies can lead to changes in nervous tissue in the brain.

Alzheimer’s disease. It results in a modification of cognitive faculties with in particular a loss of memory or reasoning. (8)

Parkinson disease. It is manifested in particular by a tremor at rest, a slowing down and a reduction in the range of motion. (9)

Drug treatments. Depending on the pathology diagnosed, certain drugs may be prescribed such as anti-inflammatory drugs.

Thrombolyse. Used during strokes, this treatment consists of breaking up the thrombi, or blood clots, with the help of drugs. (4)

Surgical treatment. Depending on the type of pathology diagnosed, surgery may be performed.

Chemotherapy, radiotherapy, targeted therapy. Depending on the type and stage of the tumor, these treatments may be implemented.

Physical examination. First, a clinical examination is performed in order to identify and assess the symptoms perceived by the patient.

Medical imaging exams. In order to establish or confirm a diagnosis, a cerebral and spinal CT scan or a cerebral MRI may in particular be performed.

biopsy. This examination consists of a sample of cells.

Lumbar puncture. This exam allows the cerebrospinal fluid to be analyzed.

Highlighted by the French neurosurgeon Paul Broca in 1861, the Broca area constitutes the area associated with the production of language.