Mobilization of intracellular calcium
At very high concentrations of about 1–2 mM, caffeine lowers the excitability threshold in muscle cells, leading to prolonged contraction. The introduction of such high doses of caffeine allows calcium to enter the muscle cell through the plasma membrane and sarcoplasmic reticulum more readily. Influx of calcium through the membranes in muscle cells requires at least 250 μM of caffeine. Normally, other toxic effects of caffeine begin to occur in concentrations over 200 μM, however average consumption averages lead to concentrations less than 100 μM. This means that calcium influx and mobilization are most likely not the cause of caffeines effect on the central nervous system, and are therefore not the cause of caffeine-induced anxiety disorder. Inhibition of phosphodiesterases
Methylxanthines such as caffeine inhibit the action of cyclic nucleotide phosphodiesterase, which normally acts to break down cAMP. Cyclic adenosine monophosphate, or cAMP, is a second messenger important in many cellular processes and is a critical factor in signal transduction. The inhibition of the phosphodiesterase would lead to a buildup of cAMP, increasing the activity of the second messenger throughout the cell. Though this mechanism is possible, it only occurs after levels of caffeine have reached a toxic level, and therefore it is unlikely to explain the mechanism of caffeine in the brain. Antagonism of adenosine receptors
There are four well-known adenosine receptors found in the body, A1, A2A, A2B, and A3.
Shaken baby syndrome (SBS), also known as abusive head trauma (AHT), is the leading cause of fatal head injuries in children younger than two years. Diagnosing the syndrome has proved both challenging and contentious for medical professionals, in that objective witnesses to the initial trauma are generally unavailable. This is said to be particularly problematic when the trauma is deemed non accidental. Some medical professionals propose that SBS is the result of respiratory abnormalities leading to hypoxia and swelling of the brain  The courtroom has become a forum for conflicting theories with which generally accepted medical literature has not been reconciled. Often there are no outwardly visible signs of trauma, despite the presence of severe internal brain and eye . Complications include seizures, visual impairment, cerebral palsy, cognitive impairment, and death.The cause may be blunt trauma, vigorous shaking, or a combination of both. Often this occurs as a result of a caregiver becoming frustrated due to the child crying. Diagnosis can be difficult as symptoms may be nonspecific. A CT scan of the head is typically recommended if a concern is present. If there are concerning findings on the CT scan, a full work-up for child abuse should occur, including an eye exam and skeletal survey. Retinal hemorrhage is highly associated with AHT, occurring in 78% of cases of AHT versus 5% of cases of non-abusive head trauma.Educating new parents appears to be beneficial in decreasing rates of the condition. SBS is estimated to occur in three to four per 10,000 babies a year.