Alertness in the context of "Hypersomnia"

An altered level of consciousness is any measure of arousal other than normal. Level of consciousness (LOC) is a measurement of a person's arousability and responsiveness to stimuli from the environment. A mildly depressed level of consciousness or alertness may be classed as lethargy; someone in this state can be aroused with little difficulty. People who are obtunded have a more depressed level of consciousness and cannot be fully aroused. Those who are not able to be aroused from a sleep-like state are said to be stuporous. Coma is the inability to make any purposeful response. Scales such as the Glasgow coma scale have been designed to measure the level of consciousness.

An altered level of consciousness can result from a variety of factors, including alterations in the chemical environment of the brain (e.g. exposure to poisons or intoxicants), insufficient oxygen or blood flow in the brain, and excessive pressure within the skull. Prolonged unconsciousness is understood to be a sign of a medical emergency. A deficit in the level of consciousness suggests that both of the cerebral hemispheres or the reticular activating system have been injured. A decreased level of consciousness correlates to increased morbidity (sickness) and mortality (death). Thus it is a valuable measure of a patient's medical and neurological status. In fact, some sources consider level of consciousness to be one of the vital signs.

Cocaine is a central nervous system stimulant and tropane alkaloid derived primarily from the leaves of two coca species native to South America: Erythroxylum coca and E. novogranatense. Coca leaves are processed into cocaine paste, a crude mix of coca alkaloids from which cocaine base is isolated and converted to cocaine hydrochloride. Cocaine was once a standard topical medication as a local anesthetic with intrinsic vasoconstrictor activity, but its high abuse potential, adverse effects, and cost have limited its use and led to its replacement by other medicines.

Street cocaine is commonly snorted, injected, or smoked as crack cocaine, with effects lasting up to 90 minutes depending on the route. Cocaine acts pharmacologically as a serotonin–norepinephrine–dopamine reuptake inhibitor (SNDRI), producing reinforcing effects such as euphoria, increased alertness, concentration, libido, and reduced fatigue and appetite.

The midbrain or mesencephalon is the uppermost portion of the brainstem connecting the diencephalon and cerebrum with the pons. It consists of the cerebral peduncles, tegmentum, and tectum.

It is functionally associated with vision, hearing, motor control, sleep and wakefulness, arousal (alertness), and temperature regulation.

The thalamus (pl.: thalami; from Greek θάλαμος, "chamber") is a large mass of gray matter on the lateral wall of the third ventricle forming the dorsal part of the diencephalon (a division of the forebrain). Nerve fibers project out of the thalamus to the cerebral cortex in all directions, known as the thalamocortical radiations, allowing hub-like exchanges of information. It has several functions, such as the relaying of sensory and motor signals to the cerebral cortex and the regulation of consciousness, sleep, and alertness.

Anatomically, the thalami are paramedian symmetrical structures (left and right), within the vertebrate brain, situated between the cerebral cortex and the midbrain. It forms during embryonic development as the main product of the diencephalon, as first recognized by the Swiss embryologist and anatomist Wilhelm His Sr. in 1893.

Stimulants (also known as central nervous system stimulants, or psychostimulants, or colloquially as uppers) are a class of psychoactive drugs that increase alertness. They are used for various purposes, such as enhancing attention, motivation, cognition, mood, and physical performance. Some stimulants occur naturally, while others are exclusively synthetic. Common stimulants include caffeine, nicotine, cocaine (including crack cocaine), amphetamine/methamphetamine, methylphenidate, and modafinil. Stimulants may be subject to varying forms of regulation, or outright prohibition, depending on jurisdiction. Most stimulants are highly addictive and damage health when addicted.

Stimulants increase activity in the sympathetic nervous system, either directly or indirectly. Prototypical stimulants increase synaptic concentrations of excitatory neurotransmitters, particularly norepinephrine and dopamine (e.g., methylphenidate). Other stimulants work by binding to the receptors of excitatory neurotransmitters (e.g., nicotine) or by blocking the activity of endogenous agents that promote sleep (e.g., caffeine). Stimulants can affect various functions, including arousal, attention, the reward system, learning, memory, and emotion. Effects range from mild stimulation to euphoria, depending on the specific drug, dose, route of administration, and inter-individual characteristics.

Methylphenidate, sold under the brand name Ritalin and Concerta, among others, is a central nervous system (CNS) stimulant used in the treatment of attention deficit hyperactivity disorder (ADHD) and narcolepsy. It may be taken by mouth or applied to the skin, and different formulations have varying durations of effect. For ADHD, the effectiveness of methylphenidate is comparable to atomoxetine but modestly lower than amphetamine. Methylphenidate reduces core ADHD symptoms and may do so in part by enhancing cognitive control of behavior (i.e., working memory and inhibitory control).

At therapeutic doses, methylphenidate increases alertness and concentration and reduces hyperactivity and impulsive behavior in individuals with ADHD. Common side effects include loss of appetite, weight loss, trouble sleeping, and small increases in heart rate and blood pressure. Long-term treatment in children has been associated with slightly slower growth. Methylphenidate can be misused; dependence and withdrawal are mainly reported with high-dose or non-medical use and are uncommon at therapeutic doses.