Experimental autoimmune encephalomyelitis, sometimes experimental allergic encephalomyelitis (EAE) is an animal model of brain inflammation. It is an inflammatory demyelinating disease of the central nervous system (CNS). It is mostly used with rodents and is widely studied as an animal model of the human CNS demyelinating diseases, including multiple sclerosis and acute disseminated encephalomyelitis (ADEM). EAE is also the prototype for T-cell-mediated autoimmune disease in general.

EAE was motivated by observations during the convalescence from viral diseases by Thomas M. Rivers, D. H. Sprunt and G. P. Berry in 1933. Their findings upon a transfer of inflamed patient tissue to primates was published in the "Journal of Experimental Medicine". An acute monophasic illness, it has been suggested that EAE is far more similar to ADEM than MS.

EAE can be induced in a number of species, including mice, rats, guinea pigs, rabbits and primates. The most commonly used antigens in rodents are spinal cord homogenate (SCH), purified myelin, myelin protein such as MBP, PLP, and MOG, or peptides of these proteins, all resulting in distinct models with different disease characteristics regarding both immunology and pathology. It may also be induced by the passive transfer of T cells specifically reactive to these myelin antigens.

Depending on the antigen used and the genetic make-up of the animal, rodents can display a monophasic bout of EAE, a relapsing-remitting form, or chronic EAE. The typical susceptible rodent will debut with clinical symptoms around two weeks after immunization and present with a relapsing-remitting disease. The archetypical first clinical symptom is weakness of tail tonus that progresses to paralysis of the tail, followed by a progression up the body to affect the hind limbs and finally the forelimbs. However, similar to MS, the disease symptoms reflect the anatomical location of the inflammatory lesions, and may also include emotional lability, sensory loss, optic neuritis, difficulties with coordination and balance (ataxia), and muscle weakness and spasms. Recovery from symptoms can be complete or partial and the time varies with symptoms and disease severity. Depending on the relapse-remission intervals, rats can have up to 3 bouts of disease within an experimental period.

Demyelination is produced by injection of brain extracts, CNS proteins (such as myelin basic protein), or peptides from such protein emulsified in an adjuvant such as complete Freund's adjuvant. The presence of the adjuvant allows the generation of inflammatory responses to the protein/peptides. In many protocols, mice are coinjected with pertussis toxin to break down the blood-brain barrier and allow immune cells access to the CNS tissue. This immunisation leads to multiple small disseminated lesions of demyelination (as well as micro-necroses) in the brain and spinal cord and the onset of clinical symptoms.

Although sharing some features, mostly demyelination, this model, first introduced in 1930s, differs from human MS in several ways. EAE either kills animals or leaves them with permanent disabilities; animals with EAE also suffer severe nerve inflammation, and the time course of EAE is entirely different from MS, being the main antigen (MBP) in charge.

Postpartum thyroid dysfunction (PPTD) is a syndrome of thyroid dysfunction occurring within the first 12 months of delivery as a consequence of the postpartum immunological rebound that follows the immune tolerant state of pregnancy. PPTD is a destructive thyroiditis with similar pathogenetic features to Hashimoto's thyroiditis.

The disease is very common with a prevalence of 5-9% of unselected postpartum women. Typically there is a transient hyperthyroid phase that is followed by a phase of hypothyroidism. Permanent hypothyroidism occurs in as much as 30% of cases after 3 years, and in 50% at 7–10 years. The hyperthyroid phase will not usually require treatment but, rarely, propanolol may be used for symptom control in severe cases. The hypothyroid phase should be treated with thyroxine if patients are symptomatic, planning to get pregnant, or if TSH levels are above 10 mU/L. Long-term follow up is necessary due to the risk of permanent hypothyroidism.

Nearly all the women with PPTD have positive TPO antibodies. This marker can be a useful screening test in early pregnancy as 50% of women with antibodies will develop thyroid dysfunction postpartum. In addition some but not all studies have shown an association between PPTD and depression so that thyroid function should be checked postpartum in women with mood changes.

Hyperthyroidism occurs in about 0.2-0.4% of all pregnancies. Most cases are due to Graves’ disease although less common causes (e.g. toxic nodules and thyroiditis) may be seen. Clinical assessment alone may occasionally be inadequate in differentiating hyperthyroidism from the hyperdynamic state of pregnancy. Distinctive clinical features of Graves’ disease include the presence of ophthalmopathy, diffuse goitre and pretibial myxoedema. Also, hyperthyroidism must be distinguished from gestational transient thyrotoxicosis, a self-limiting hyperthyroid state due to the thyroid stimulatory effects of beta-hCG . This distinction is important since the latter condition is typically mild and will not usually require specific antithyroid treatment. Red cell zinc may also be useful in differentiating the two. Hyperthyroidism due to Graves’ disease may worsen in the first trimester of pregnancy, remit in later pregnancy, and subsequently relapse in the postpartum.